SlideShare a Scribd company logo
1 of 79
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
1
Chapter 2 Elementary Programming
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
2
Motivations
In the preceding chapter, you learned how to
create, compile, and run a Java program. Starting
from this chapter, you will learn how to solve
practical problems programmatically. Through
these problems, you will learn Java primitive data
types and related subjects, such as variables,
constants, data types, operators, expressions, and
input and output.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
3
Objectives
 To write Java programs to perform simple computations (§2.2).
 To obtain input from the console using the Scanner class (§2.3).
 To use identifiers to name variables, constants, methods, and classes (§2.4).
 To use variables to store data (§§2.5–2.6).
 To program with assignment statements and assignment expressions (§2.6).
 To use constants to store permanent data (§2.7).
 To name classes, methods, variables, and constants by following their naming conventions (§2.8).
 To explore Java numeric primitive data types: byte, short, int, long, float, and double (§2.9.1).
 To perform operations using operators +, -, *, /, and % (§2.9.2).
 To perform exponent operations using Math.pow(a, b) (§2.9.3).
 To write integer literals, floating-point literals, and literals in scientific notation (§2.10).
 To write and evaluate numeric expressions (§2.11).
 To obtain the current system time using System.currentTimeMillis() (§2.12).
 To use augmented assignment operators (§2.13).
 To distinguish between postincrement and preincrement and between postdecrement and
predecrement (§2.14).
 To cast the value of one type to another type (§2.15).
 To describe the software development process and apply it to develop the loan payment program
(§2.16).
 To represent characters using the char type (§2.17).
 To represent a string using the String type (§2.18).
 To obtain input using the JOptionPane input dialog boxes (§2.19).
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
4
Introducing Programming with an
Example
Listing 2.1 Computing the Area of a Circle
This program computes the area of the circle.
ComputeArea
Run
IMPORTANT NOTE: (1) To enable the buttons, you must
download the entire slide file slide.zip and unzip the files into a
directory (e.g., c:slide) . (2) You must have installed JDK and set
JDK’s bin directory in your environment path (e.g., c:Program
Filesjavajdk1.7.0bin in your environment path. (3) If you are
using Office 2010, check PowerPoint2010.doc located in the same
folder with this ppt file.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
5
Trace a Program Execution
public class ComputeArea {
/** Main method */
public static void main(String[] args) {
double radius;
double area;
// Assign a radius
radius = 20;
// Compute area
area = radius * radius * 3.14159;
// Display results
System.out.println("The area for the circle of radius " +
radius + " is " + area);
}
}
no value
radius
allocate memory
for radius
animation
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
6
Trace a Program Execution
public class ComputeArea {
/** Main method */
public static void main(String[] args) {
double radius;
double area;
// Assign a radius
radius = 20;
// Compute area
area = radius * radius * 3.14159;
// Display results
System.out.println("The area for the circle of radius " +
radius + " is " + area);
}
}
no value
radius
memory
no value
area
allocate memory
for area
animation
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
7
Trace a Program Execution
public class ComputeArea {
/** Main method */
public static void main(String[] args) {
double radius;
double area;
// Assign a radius
radius = 20;
// Compute area
area = radius * radius * 3.14159;
// Display results
System.out.println("The area for the circle of radius " +
radius + " is " + area);
}
}
20
radius
no value
area
assign 20 to radius
animation
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
8
Trace a Program Execution
public class ComputeArea {
/** Main method */
public static void main(String[] args) {
double radius;
double area;
// Assign a radius
radius = 20;
// Compute area
area = radius * radius * 3.14159;
// Display results
System.out.println("The area for the circle of radius " +
radius + " is " + area);
}
}
20
radius
memory
1256.636
area
compute area and assign it
to variable area
animation
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
9
Trace a Program Execution
public class ComputeArea {
/** Main method */
public static void main(String[] args) {
double radius;
double area;
// Assign a radius
radius = 20;
// Compute area
area = radius * radius * 3.14159;
// Display results
System.out.println("The area for the circle of radius " +
radius + " is " + area);
}
}
20
radius
memory
1256.636
area
print a message to the
console
animation
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
10
Reading Input from the Console
1. Create a Scanner object
Scanner input = new Scanner(System.in);
2. Use the methods next(), nextByte(), nextShort(),
nextInt(), nextLong(), nextFloat(), nextDouble(), or
nextBoolean() to obtain to a string, byte, short, int, long,
float, double, or boolean value. For example,
System.out.print("Enter a double value: ");
Scanner input = new Scanner(System.in);
double d = input.nextDouble();
ComputeAreaWithConsoleInput
Run
ComputeAverage
Run
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
11
Identifiers
 An identifier is a sequence of characters that consist of
letters, digits, underscores (_), and dollar signs ($).
 An identifier must start with a letter, an underscore (_),
or a dollar sign ($). It cannot start with a digit.
– An identifier cannot be a reserved word. (See Appendix A,
“Java Keywords,” for a list of reserved words).
 An identifier cannot be true, false, or
null.
 An identifier can be of any length.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
12
Variables
// Compute the first area
radius = 1.0;
area = radius * radius * 3.14159;
System.out.println("The area is “ +
area + " for radius "+radius);
// Compute the second area
radius = 2.0;
area = radius * radius * 3.14159;
System.out.println("The area is “ +
area + " for radius "+radius);
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
13
Declaring Variables
int x; // Declare x to be an
// integer variable;
double radius; // Declare radius to
// be a double variable;
char a; // Declare a to be a
// character variable;
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
14
Assignment Statements
x = 1; // Assign 1 to x;
radius = 1.0; // Assign 1.0 to radius;
a = 'A'; // Assign 'A' to a;
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
15
Declaring and Initializing
in One Step
 int x = 1;
 double d = 1.4;
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
16
Named Constants
final datatype CONSTANTNAME = VALUE;
final double PI = 3.14159;
final int SIZE = 3;
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
17
Naming Conventions
 Choose meaningful and descriptive names.
 Variables and method names:
– Use lowercase. If the name consists of several
words, concatenate all in one, use lowercase
for the first word, and capitalize the first letter
of each subsequent word in the name. For
example, the variables radius and area, and
the method computeArea.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
18
Naming Conventions, cont.
 Class names:
– Capitalize the first letter of each word in
the name. For example, the class name
ComputeArea.
 Constants:
– Capitalize all letters in constants, and use
underscores to connect words. For
example, the constant PI and
MAX_VALUE
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
19
Numerical Data Types
Name Range Storage Size
byte –27 to 27 – 1 (-128 to 127) 8-bit signed
short –215 to 215 – 1 (-32768 to 32767) 16-bit signed
int –231 to 231 – 1 (-2147483648 to 2147483647) 32-bit signed
long –263 to 263 – 1 64-bit signed
(i.e., -9223372036854775808 to 9223372036854775807)
float Negative range: 32-bit IEEE 754
-3.4028235E+38 to -1.4E-45
Positive range:
1.4E-45 to 3.4028235E+38
double Negative range: 64-bit IEEE 754
-1.7976931348623157E+308 to -4.9E-324
Positive range:
4.9E-324 to 1.7976931348623157E+308
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
20
Numeric Operators
Name Meaning Example Result
+ Addition 34 + 1 35
- Subtraction 34.0 – 0.1 33.9
* Multiplication 300 * 30 9000
/ Division 1.0 / 2.0 0.5
% Remainder 20 % 3 2
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
21
Integer Division
+, -, *, /, and %
5 / 2 yields an integer 2.
5.0 / 2 yields a double value 2.5
5 % 2 yields 1 (the remainder of the division)
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
22
Remainder Operator
Remainder is very useful in programming. For example, an
even number % 2 is always 0 and an odd number % 2 is always
1. So you can use this property to determine whether a number
is even or odd. Suppose today is Saturday and you and your
friends are going to meet in 10 days. What day is in 10
days? You can find that day is Tuesday using the following
expression:
Saturday is the 6th
day in a week
A week has 7 days
After 10 days
The 2nd
day in a week is Tuesday
(6 + 10) % 7 is 2
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
23
Problem: Displaying Time
Write a program that obtains hours and
minutes from seconds.
DisplayTime Run
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
24
NOTE
Calculations involving floating-point numbers are
approximated because these numbers are not stored
with complete accuracy. For example,
System.out.println(1.0 - 0.1 - 0.1 - 0.1 - 0.1 - 0.1);
displays 0.5000000000000001, not 0.5, and
System.out.println(1.0 - 0.9);
displays 0.09999999999999998, not 0.1. Integers are
stored precisely. Therefore, calculations with integers
yield a precise integer result.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
25
Exponent Operations
System.out.println(Math.pow(2, 3));
// Displays 8.0
System.out.println(Math.pow(4, 0.5));
// Displays 2.0
System.out.println(Math.pow(2.5, 2));
// Displays 6.25
System.out.println(Math.pow(2.5, -2));
// Displays 0.16
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
26
Number Literals
A literal is a constant value that appears directly
in the program. For example, 34, 1,000,000, and
5.0 are literals in the following statements:
int i = 34;
long x = 1000000;
double d = 5.0;
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
27
Integer Literals
An integer literal can be assigned to an integer variable as
long as it can fit into the variable. A compilation error
would occur if the literal were too large for the variable to
hold. For example, the statement byte b = 1000 would
cause a compilation error, because 1000 cannot be stored
in a variable of the byte type.
An integer literal is assumed to be of the int type, whose
value is between -231 (-2147483648) to 231–1
(2147483647). To denote an integer literal of the long
type, append it with the letter L or l. L is preferred because
l (lowercase L) can easily be confused with 1 (the digit
one).
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
28
Floating-Point Literals
Floating-point literals are written with a decimal
point. By default, a floating-point literal is treated
as a double type value. For example, 5.0 is
considered a double value, not a float value. You
can make a number a float by appending the letter f
or F, and make a number a double by appending
the letter d or D. For example, you can use 100.2f
or 100.2F for a float number, and 100.2d or 100.2D
for a double number.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
29
Scientific Notation
Floating-point literals can also be specified in
scientific notation, for example, 1.23456e+2,
same as 1.23456e2, is equivalent to 123.456, and
1.23456e-2 is equivalent to 0.0123456. E (or e)
represents an exponent and it can be either in
lowercase or uppercase.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
30
Arithmetic Expressions
)
9
4
(
9
)
)(
5
(
10
5
4
3
y
x
x
x
c
b
a
y
x 







is translated to
(3+4*x)/5 – 10*(y-5)*(a+b+c)/x + 9*(4/x + (9+x)/y)
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
31
How to Evaluate an Expression
Though Java has its own way to evaluate an
expression behind the scene, the result of a Java
expression and its corresponding arithmetic expression
are the same. Therefore, you can safely apply the
arithmetic rule for evaluating a Java expression.
3 + 4 * 4 + 5 * (4 + 3) - 1
3 + 4 * 4 + 5 * 7 – 1
3 + 16 + 5 * 7 – 1
3 + 16 + 35 – 1
19 + 35 – 1
54 - 1
53
(1) inside parentheses first
(2) multiplication
(3) multiplication
(4) addition
(6) subtraction
(5) addition
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
32
Problem: Converting Temperatures
Write a program that converts a Fahrenheit degree
to Celsius using the formula:
FahrenheitToCelsius Run
)
32
)(
(9
5

 fahrenheit
celsius
Note: you have to write
celsius = (5.0 / 9) * (fahrenheit – 32)
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
33
Problem: Displaying Current Time
Write a program that displays current time in GMT in the
format hour:minute:second such as 1:45:19.
The currentTimeMillis method in the System class returns
the current time in milliseconds since the midnight, January
1, 1970 GMT. (1970 was the year when the Unix operating
system was formally introduced.) You can use this method
to obtain the current time, and then compute the current
second, minute, and hour as follows.
ShowCurrentTime
Run
Elapsed
time
Unix Epoch
01-01-1970
00:00:00 GMT
Current Time
Time
System.currentTimeMills()
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
34
Shortcut Assignment Operators
Operator Example Equivalent
+= i += 8 i = i + 8
-= f -= 8.0 f = f - 8.0
*= i *= 8 i = i * 8
/= i /= 8 i = i / 8
%= i %= 8 i = i % 8
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
35
Increment and
Decrement Operators
Operator Name Description
++var preincrement The expression (++var) increments var by 1 and evaluates
to the new value in var after the increment.
var++ postincrement The expression (var++) evaluates to the original value
in var and increments var by 1.
--var predecrement The expression (--var) decrements var by 1 and evaluates
to the new value in var after the decrement.
var-- postdecrement The expression (var--) evaluates to the original value
in var and decrements var by 1.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
36
Increment and
Decrement Operators, cont.
int i = 10;
int newNum = 10 * i++; int newNum = 10 * i;
i = i + 1;
Same effect as
int i = 10;
int newNum = 10 * (++i); i = i + 1;
int newNum = 10 * i;
Same effect as
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
37
Increment and
Decrement Operators, cont.
Using increment and decrement operators makes
expressions short, but it also makes them complex and
difficult to read. Avoid using these operators in expressions
that modify multiple variables, or the same variable for
multiple times such as this: int k = ++i + i.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
38
Assignment Expressions and
Assignment Statements
Prior to Java 2, all the expressions can be used as
statements. Since Java 2, only the following types of
expressions can be statements:
variable op= expression; // Where op is +, -, *, /, or %
++variable;
variable++;
--variable;
variable--;
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
39
Numeric Type Conversion
Consider the following statements:
byte i = 100;
long k = i * 3 + 4;
double d = i * 3.1 + k / 2;
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
40
Conversion Rules
When performing a binary operation involving two
operands of different types, Java automatically
converts the operand based on the following rules:
1. If one of the operands is double, the other is
converted into double.
2. Otherwise, if one of the operands is float, the other is
converted into float.
3. Otherwise, if one of the operands is long, the other is
converted into long.
4. Otherwise, both operands are converted into int.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
41
Type Casting
Implicit casting
double d = 3; (type widening)
Explicit casting
int i = (int)3.0; (type narrowing)
int i = (int)3.9; (Fraction part is
truncated)
What is wrong? int x = 5 / 2.0;
byte, short, int, long, float, double
range increases
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
42
Problem: Keeping Two Digits After
Decimal Points
Write a program that displays the sales tax with two
digits after the decimal point.
SalesTax Run
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
43
Casting in an Augmented Expression
In Java, an augmented expression of the form x1 op=
x2 is implemented as x1 = (T)(x1 op x2), where T is
the type for x1. Therefore, the following code is
correct.
int sum = 0;
sum += 4.5; // sum becomes 4 after this statement
sum += 4.5 is equivalent to sum = (int)(sum + 4.5).
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
44
Software Development Process
Requirement
Specification
System
Analysis
System
Design
Testing
Implementation
Maintenance
Deployment
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
45
Requirement Specification
Requirement
Specification
System
Analysis
System
Design
Testing
Implementation
Maintenance
Deployment
A formal process that seeks to understand
the problem and document in detail what
the software system needs to do. This
phase involves close interaction between
users and designers.
Most of the examples in this book are simple,
and their requirements are clearly stated. In
the real world, however, problems are not
well defined. You need to study a problem
carefully to identify its requirements.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
46
System Analysis
Requirement
Specification
System
Analysis
System
Design
Testing
Implementation
Maintenance
Deployment
Seeks to analyze the business
process in terms of data flow, and
to identify the system’s input and
output.
Part of the analysis entails modeling
the system’s behavior. The model is
intended to capture the essential
elements of the system and to define
services to the system.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
47
System Design
Requirement
Specification
System
Analysis
System
Design
Testing
Implementation
Maintenance
Deployment
The process of designing the
system’s components.
This phase involves the use of many levels
of abstraction to decompose the problem into
manageable components, identify classes and
interfaces, and establish relationships among
the classes and interfaces.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
48
IPO
Requirement
Specification
System
Analysis
System
Design
Input, Process, Output
Testing
Implementation
Maintenance
Deployment
The essence of system analysis and design is input,
process, and output. This is called IPO.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
49
Implementation
Requirement
Specification
System
Analysis
System
Design
Testing
Implementation
Maintenance
Deployment
The process of translating the
system design into programs.
Separate programs are written for
each component and put to work
together.
This phase requires the use of a
programming language like Java.
The implementation involves
coding, testing, and debugging.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
50
Testing
Requirement
Specification
System
Analysis
System
Design
Testing
Implementation
Maintenance
Deployment
Ensures that the code meets the
requirements specification and
weeds out bugs.
An independent team of software
engineers not involved in the design
and implementation of the project
usually conducts such testing.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
51
Deployment
Requirement
Specification
System
Analysis
System
Design
Testing
Implementation
Maintenance
Deployment
Deployment makes the project
available for use.
For a Java applet, this means
installing it on a Web server; for a
Java application, installing it on the
client's computer.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
52
Maintenance
Requirement
Specification
System
Analysis
System
Design
Testing
Implementation
Maintenance
Deployment
Maintenance is concerned with
changing and improving the
product.
A software product must continue to
perform and improve in a changing
environment. This requires periodic
upgrades of the product to fix newly
discovered bugs and incorporate changes.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
53
Problem:
Computing Loan Payments
ComputeLoan Run
This program lets the user enter the interest
rate, number of years, and loan amount, and
computes monthly payment and total
payment.
12
)
1
(
1
1 




ars
numberOfYe
erestRate
monthlyInt
erestRate
monthlyInt
loanAmount
ment
monthlyPay
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
54
Character Data Type
char letter = 'A'; (ASCII)
char numChar = '4'; (ASCII)
char letter = 'u0041'; (Unicode)
char numChar = 'u0034'; (Unicode)
Four hexadecimal digits.
NOTE: The increment and decrement operators can also be used
on char variables to get the next or preceding Unicode character.
For example, the following statements display character b.
char ch = 'a';
System.out.println(++ch);
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
55
Unicode Format
Java characters use Unicode, a 16-bit encoding scheme
established by the Unicode Consortium to support the
interchange, processing, and display of written texts in the
world’s diverse languages. Unicode takes two bytes,
preceded by u, expressed in four hexadecimal numbers
that run from 'u0000' to 'uFFFF'. So, Unicode can
represent 65535 + 1 characters.
Unicode u03b1 u03b2 u03b3 for three Greek
letters
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
56
Problem: Displaying Unicodes
Write a program that displays two Chinese
characters and three Greek letters.
DisplayUnicode Run
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
57
Escape Sequences for Special Characters
Description Escape Sequence Unicode
Backspace b u0008
Tab t u0009
Linefeed n u000A
Carriage return r u000D
Backslash  u005C
Single Quote ' u0027
Double Quote " u0022
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
58
Appendix B: ASCII Character Set
ASCII Character Set is a subset of the Unicode from u0000 to u007f
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
59
ASCII Character Set, cont.
ASCII Character Set is a subset of the Unicode from u0000 to u007f
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
60
Casting between char and
Numeric Types
int i = 'a'; // Same as int i = (int)'a';
char c = 97; // Same as char c = (char)97;
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
61
Problem: Monetary Units
This program lets the user enter the amount in
decimal representing dollars and cents and output
a report listing the monetary equivalent in single
dollars, quarters, dimes, nickels, and pennies.
Your program should report maximum number of
dollars, then the maximum number of quarters,
and so on, in this order.
ComputeChange Run
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
62
Trace ComputeChange
int remainingAmount = (int)(amount * 100);
// Find the number of one dollars
int numberOfOneDollars = remainingAmount / 100;
remainingAmount = remainingAmount % 100;
// Find the number of quarters in the remaining amount
int numberOfQuarters = remainingAmount / 25;
remainingAmount = remainingAmount % 25;
// Find the number of dimes in the remaining amount
int numberOfDimes = remainingAmount / 10;
remainingAmount = remainingAmount % 10;
// Find the number of nickels in the remaining amount
int numberOfNickels = remainingAmount / 5;
remainingAmount = remainingAmount % 5;
// Find the number of pennies in the remaining amount
int numberOfPennies = remainingAmount;
1156
remainingAmount
remainingAmount
initialized
Suppose amount is 11.56
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
63
Trace ComputeChange
int remainingAmount = (int)(amount * 100);
// Find the number of one dollars
int numberOfOneDollars = remainingAmount / 100;
remainingAmount = remainingAmount % 100;
// Find the number of quarters in the remaining amount
int numberOfQuarters = remainingAmount / 25;
remainingAmount = remainingAmount % 25;
// Find the number of dimes in the remaining amount
int numberOfDimes = remainingAmount / 10;
remainingAmount = remainingAmount % 10;
// Find the number of nickels in the remaining amount
int numberOfNickels = remainingAmount / 5;
remainingAmount = remainingAmount % 5;
// Find the number of pennies in the remaining amount
int numberOfPennies = remainingAmount;
1156
remainingAmount
Suppose amount is 11.56
11
numberOfOneDollars
numberOfOneDollars
assigned
animation
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
64
Trace ComputeChange
int remainingAmount = (int)(amount * 100);
// Find the number of one dollars
int numberOfOneDollars = remainingAmount / 100;
remainingAmount = remainingAmount % 100;
// Find the number of quarters in the remaining amount
int numberOfQuarters = remainingAmount / 25;
remainingAmount = remainingAmount % 25;
// Find the number of dimes in the remaining amount
int numberOfDimes = remainingAmount / 10;
remainingAmount = remainingAmount % 10;
// Find the number of nickels in the remaining amount
int numberOfNickels = remainingAmount / 5;
remainingAmount = remainingAmount % 5;
// Find the number of pennies in the remaining amount
int numberOfPennies = remainingAmount;
56
remainingAmount
Suppose amount is 11.56
11
numberOfOneDollars
remainingAmount
updated
animation
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
65
Trace ComputeChange
int remainingAmount = (int)(amount * 100);
// Find the number of one dollars
int numberOfOneDollars = remainingAmount / 100;
remainingAmount = remainingAmount % 100;
// Find the number of quarters in the remaining amount
int numberOfQuarters = remainingAmount / 25;
remainingAmount = remainingAmount % 25;
// Find the number of dimes in the remaining amount
int numberOfDimes = remainingAmount / 10;
remainingAmount = remainingAmount % 10;
// Find the number of nickels in the remaining amount
int numberOfNickels = remainingAmount / 5;
remainingAmount = remainingAmount % 5;
// Find the number of pennies in the remaining amount
int numberOfPennies = remainingAmount;
56
remainingAmount
Suppose amount is 11.56
11
numberOfOneDollars
2
numberOfOneQuarters
numberOfOneQuarters
assigned
animation
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
66
Trace ComputeChange
int remainingAmount = (int)(amount * 100);
// Find the number of one dollars
int numberOfOneDollars = remainingAmount / 100;
remainingAmount = remainingAmount % 100;
// Find the number of quarters in the remaining amount
int numberOfQuarters = remainingAmount / 25;
remainingAmount = remainingAmount % 25;
// Find the number of dimes in the remaining amount
int numberOfDimes = remainingAmount / 10;
remainingAmount = remainingAmount % 10;
// Find the number of nickels in the remaining amount
int numberOfNickels = remainingAmount / 5;
remainingAmount = remainingAmount % 5;
// Find the number of pennies in the remaining amount
int numberOfPennies = remainingAmount;
6
remainingAmount
Suppose amount is 11.56
11
numberOfOneDollars
2
numberOfQuarters
remainingAmount
updated
animation
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
67
The String Type
The char type only represents one character. To represent a string
of characters, use the data type called String. For example,
String message = "Welcome to Java";
String is actually a predefined class in the Java library just like the
System class and JOptionPane class. The String type is not a
primitive type. It is known as a reference type. Any Java class can
be used as a reference type for a variable. Reference data types
will be thoroughly discussed in Chapter 8, “Objects and Classes.”
For the time being, you just need to know how to declare a String
variable, how to assign a string to the variable, and how to
concatenate strings.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
68
String Concatenation
// Three strings are concatenated
String message = "Welcome " + "to " + "Java";
// String Chapter is concatenated with number 2
String s = "Chapter" + 2; // s becomes Chapter2
// String Supplement is concatenated with character B
String s1 = "Supplement" + 'B'; // s1 becomes SupplementB
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
69
Debugging
Logic errors are called bugs. The process of finding and
correcting errors is called debugging. A common approach
to debugging is to use a combination of methods to narrow
down to the part of the program where the bug is located.
You can hand-trace the program (i.e., catch errors by
reading the program), or you can insert print statements in
order to show the values of the variables or the execution
flow of the program. This approach might work for a
short, simple program. But for a large, complex program,
the most effective approach for debugging is to use a
debugger utility.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
70
Debugger
Debugger is a program that facilitates debugging.
You can use a debugger to
Execute a single statement at a time.
Trace into or stepping over a method.
Set breakpoints.
Display variables.
Display call stack.
Modify variables.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
71
JOptionPane Input
This book provides two ways of obtaining input.
1. Using the Scanner class (console input)
2. Using JOptionPane input dialogs
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
72
Getting Input from Input Dialog Boxes
String input = JOptionPane.showInputDialog(
"Enter an input");
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
73
Getting Input from Input Dialog Boxes
String string = JOptionPane.showInputDialog(
null, “Prompting Message”, “Dialog Title”,
JOptionPane.QUESTION_MESSAGE);
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
74
Two Ways to Invoke the Method
There are several ways to use the showInputDialog method. For
the time being, you only need to know two ways to invoke it.
One is to use a statement as shown in the example:
String string = JOptionPane.showInputDialog(null, x,
y, JOptionPane.QUESTION_MESSAGE);
where x is a string for the prompting message, and y is a string for
the title of the input dialog box.
The other is to use a statement like this:
JOptionPane.showInputDialog(x);
where x is a string for the prompting message.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
75
Converting Strings to Integers
The input returned from the input dialog box is a string. If
you enter a numeric value such as 123, it returns “123”.
To obtain the input as a number, you have to convert a
string into a number.
To convert a string into an int value, you can use the
static parseInt method in the Integer class as follows:
int intValue = Integer.parseInt(intString);
where intString is a numeric string such as “123”.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
76
Converting Strings to Doubles
To convert a string into a double value, you can use the
static parseDouble method in the Double class as follows:
double doubleValue =Double.parseDouble(doubleString);
where doubleString is a numeric string such as “123.45”.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
77
Problem: Computing Loan Payments
Using Input Dialogs
ComputeLoanUsingInputDialog Run
Same as the preceding program for computing loan
payments, except that the input is entered from the
input dialogs and the output is displayed in an
output dialog.
12
)
1
(
1
1 



ars
numberOfYe
erestRate
monthlyInt
erestRate
monthlyInt
loanAmount
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
78
Debugging in NetBeans
Supplement II.E, Learning Java Effectively with
NetBeans
Companion
Website
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All
rights reserved.
79
Debugging in Eclipse
Supplement II.G, Learning Java Effectively with
NetBeans
Companion
Website

More Related Content

Similar to 02slidLarge value of face area Large value of face area

Similar to 02slidLarge value of face area Large value of face area (20)

05slide
05slide05slide
05slide
 
Java final lab
Java final labJava final lab
Java final lab
 
03slide.ppt
03slide.ppt03slide.ppt
03slide.ppt
 
java-programming.pdf
java-programming.pdfjava-programming.pdf
java-programming.pdf
 
Core java
Core javaCore java
Core java
 
Wap to implement bitwise operators
Wap to implement bitwise operatorsWap to implement bitwise operators
Wap to implement bitwise operators
 
Interface in java
Interface in javaInterface in java
Interface in java
 
11slide.ppt
11slide.ppt11slide.ppt
11slide.ppt
 
C# Variables and Operators
C# Variables and OperatorsC# Variables and Operators
C# Variables and Operators
 
Java Programs Lab File
Java Programs Lab FileJava Programs Lab File
Java Programs Lab File
 
Java ppt Gandhi Ravi (gandhiri@gmail.com)
Java ppt  Gandhi Ravi  (gandhiri@gmail.com)Java ppt  Gandhi Ravi  (gandhiri@gmail.com)
Java ppt Gandhi Ravi (gandhiri@gmail.com)
 
I/O (imput/output) [JAVA]
I/O  (imput/output) [JAVA]I/O  (imput/output) [JAVA]
I/O (imput/output) [JAVA]
 
Unit No. 1 Introduction to Java.pptx
Unit No. 1 Introduction to Java.pptxUnit No. 1 Introduction to Java.pptx
Unit No. 1 Introduction to Java.pptx
 
famous placement papers
famous placement papersfamous placement papers
famous placement papers
 
Implementation of interface9 cm604.30
Implementation of interface9 cm604.30Implementation of interface9 cm604.30
Implementation of interface9 cm604.30
 
1. basics of python
1. basics of python1. basics of python
1. basics of python
 
10slide.ppt
10slide.ppt10slide.ppt
10slide.ppt
 
Example for Abstract Class and Interface.pdf
Example for Abstract Class and Interface.pdfExample for Abstract Class and Interface.pdf
Example for Abstract Class and Interface.pdf
 
01-ch01-1-println.ppt java introduction one
01-ch01-1-println.ppt java introduction one01-ch01-1-println.ppt java introduction one
01-ch01-1-println.ppt java introduction one
 
Java PRACTICAL file
Java PRACTICAL fileJava PRACTICAL file
Java PRACTICAL file
 

More from AhmadHashlamon

kinectic_and_drug_stability microemulsions
kinectic_and_drug_stability microemulsionskinectic_and_drug_stability microemulsions
kinectic_and_drug_stability microemulsionsAhmadHashlamon
 
04slidemicroemulsions microemulsions microemulsions microemulsions microemuls...
04slidemicroemulsions microemulsions microemulsions microemulsions microemuls...04slidemicroemulsions microemulsions microemulsions microemulsions microemuls...
04slidemicroemulsions microemulsions microemulsions microemulsions microemuls...AhmadHashlamon
 
skeletal musclemicroemulsions microemulsions microemulsions microemulsions mi...
skeletal musclemicroemulsions microemulsions microemulsions microemulsions mi...skeletal musclemicroemulsions microemulsions microemulsions microemulsions mi...
skeletal musclemicroemulsions microemulsions microemulsions microemulsions mi...AhmadHashlamon
 
microemulsions microemulsions microemulsions microemulsions
microemulsions microemulsions microemulsions microemulsionsmicroemulsions microemulsions microemulsions microemulsions
microemulsions microemulsions microemulsions microemulsionsAhmadHashlamon
 
Herbal_Medicine_Developmggggffgfent.pptx
Herbal_Medicine_Developmggggffgfent.pptxHerbal_Medicine_Developmggggffgfent.pptx
Herbal_Medicine_Developmggggffgfent.pptxAhmadHashlamon
 
performulation studies.pptx
performulation studies.pptxperformulation studies.pptx
performulation studies.pptxAhmadHashlamon
 
Oxidation-Reduction-Reactions-and-Titrations.ppt
Oxidation-Reduction-Reactions-and-Titrations.pptOxidation-Reduction-Reactions-and-Titrations.ppt
Oxidation-Reduction-Reactions-and-Titrations.pptAhmadHashlamon
 
Complexometric-Titrations part 2.ppt
Complexometric-Titrations part 2.pptComplexometric-Titrations part 2.ppt
Complexometric-Titrations part 2.pptAhmadHashlamon
 
Data-Handling part 2.ppt
Data-Handling part 2.pptData-Handling part 2.ppt
Data-Handling part 2.pptAhmadHashlamon
 
1 Precipitation-titrations.ppt
1 Precipitation-titrations.ppt1 Precipitation-titrations.ppt
1 Precipitation-titrations.pptAhmadHashlamon
 
Complexometric-Titrations part 1.ppt
Complexometric-Titrations part 1.pptComplexometric-Titrations part 1.ppt
Complexometric-Titrations part 1.pptAhmadHashlamon
 
Data-Handling part 1 .ppt
Data-Handling part 1 .pptData-Handling part 1 .ppt
Data-Handling part 1 .pptAhmadHashlamon
 
Acid-Base-Equilibria.ppt
Acid-Base-Equilibria.pptAcid-Base-Equilibria.ppt
Acid-Base-Equilibria.pptAhmadHashlamon
 
General-Equilibrium-Concepts.ppt
General-Equilibrium-Concepts.pptGeneral-Equilibrium-Concepts.ppt
General-Equilibrium-Concepts.pptAhmadHashlamon
 
Stoichiometric-calculations part 2.ppt
Stoichiometric-calculations part 2.pptStoichiometric-calculations part 2.ppt
Stoichiometric-calculations part 2.pptAhmadHashlamon
 
Stoichiometric-calculations part 1.ppt
Stoichiometric-calculations part 1.pptStoichiometric-calculations part 1.ppt
Stoichiometric-calculations part 1.pptAhmadHashlamon
 

More from AhmadHashlamon (20)

kinectic_and_drug_stability microemulsions
kinectic_and_drug_stability microemulsionskinectic_and_drug_stability microemulsions
kinectic_and_drug_stability microemulsions
 
04slidemicroemulsions microemulsions microemulsions microemulsions microemuls...
04slidemicroemulsions microemulsions microemulsions microemulsions microemuls...04slidemicroemulsions microemulsions microemulsions microemulsions microemuls...
04slidemicroemulsions microemulsions microemulsions microemulsions microemuls...
 
skeletal musclemicroemulsions microemulsions microemulsions microemulsions mi...
skeletal musclemicroemulsions microemulsions microemulsions microemulsions mi...skeletal musclemicroemulsions microemulsions microemulsions microemulsions mi...
skeletal musclemicroemulsions microemulsions microemulsions microemulsions mi...
 
microemulsions microemulsions microemulsions microemulsions
microemulsions microemulsions microemulsions microemulsionsmicroemulsions microemulsions microemulsions microemulsions
microemulsions microemulsions microemulsions microemulsions
 
Herbal_Medicine_Developmggggffgfent.pptx
Herbal_Medicine_Developmggggffgfent.pptxHerbal_Medicine_Developmggggffgfent.pptx
Herbal_Medicine_Developmggggffgfent.pptx
 
C13NMR 2.pptx
C13NMR 2.pptxC13NMR 2.pptx
C13NMR 2.pptx
 
Clothes fiber.pptx
Clothes fiber.pptxClothes fiber.pptx
Clothes fiber.pptx
 
performulation studies.pptx
performulation studies.pptxperformulation studies.pptx
performulation studies.pptx
 
introduction.pptx
introduction.pptxintroduction.pptx
introduction.pptx
 
chapter_3_part_1.pptx
chapter_3_part_1.pptxchapter_3_part_1.pptx
chapter_3_part_1.pptx
 
Oxidation-Reduction-Reactions-and-Titrations.ppt
Oxidation-Reduction-Reactions-and-Titrations.pptOxidation-Reduction-Reactions-and-Titrations.ppt
Oxidation-Reduction-Reactions-and-Titrations.ppt
 
Complexometric-Titrations part 2.ppt
Complexometric-Titrations part 2.pptComplexometric-Titrations part 2.ppt
Complexometric-Titrations part 2.ppt
 
Data-Handling part 2.ppt
Data-Handling part 2.pptData-Handling part 2.ppt
Data-Handling part 2.ppt
 
1 Precipitation-titrations.ppt
1 Precipitation-titrations.ppt1 Precipitation-titrations.ppt
1 Precipitation-titrations.ppt
 
Complexometric-Titrations part 1.ppt
Complexometric-Titrations part 1.pptComplexometric-Titrations part 1.ppt
Complexometric-Titrations part 1.ppt
 
Data-Handling part 1 .ppt
Data-Handling part 1 .pptData-Handling part 1 .ppt
Data-Handling part 1 .ppt
 
Acid-Base-Equilibria.ppt
Acid-Base-Equilibria.pptAcid-Base-Equilibria.ppt
Acid-Base-Equilibria.ppt
 
General-Equilibrium-Concepts.ppt
General-Equilibrium-Concepts.pptGeneral-Equilibrium-Concepts.ppt
General-Equilibrium-Concepts.ppt
 
Stoichiometric-calculations part 2.ppt
Stoichiometric-calculations part 2.pptStoichiometric-calculations part 2.ppt
Stoichiometric-calculations part 2.ppt
 
Stoichiometric-calculations part 1.ppt
Stoichiometric-calculations part 1.pptStoichiometric-calculations part 1.ppt
Stoichiometric-calculations part 1.ppt
 

Recently uploaded

Top 10 Interactive Website Design Trends in 2024.pptx
Top 10 Interactive Website Design Trends in 2024.pptxTop 10 Interactive Website Design Trends in 2024.pptx
Top 10 Interactive Website Design Trends in 2024.pptxDyna Gilbert
 
定制(UAL学位证)英国伦敦艺术大学毕业证成绩单原版一比一
定制(UAL学位证)英国伦敦艺术大学毕业证成绩单原版一比一定制(UAL学位证)英国伦敦艺术大学毕业证成绩单原版一比一
定制(UAL学位证)英国伦敦艺术大学毕业证成绩单原版一比一Fs
 
A Good Girl's Guide to Murder (A Good Girl's Guide to Murder, #1)
A Good Girl's Guide to Murder (A Good Girl's Guide to Murder, #1)A Good Girl's Guide to Murder (A Good Girl's Guide to Murder, #1)
A Good Girl's Guide to Murder (A Good Girl's Guide to Murder, #1)Christopher H Felton
 
Magic exist by Marta Loveguard - presentation.pptx
Magic exist by Marta Loveguard - presentation.pptxMagic exist by Marta Loveguard - presentation.pptx
Magic exist by Marta Loveguard - presentation.pptxMartaLoveguard
 
Call Girls South Delhi Delhi reach out to us at ☎ 9711199012
Call Girls South Delhi Delhi reach out to us at ☎ 9711199012Call Girls South Delhi Delhi reach out to us at ☎ 9711199012
Call Girls South Delhi Delhi reach out to us at ☎ 9711199012rehmti665
 
Packaging the Monolith - PHP Tek 2024 (Breaking it down one bite at a time)
Packaging the Monolith - PHP Tek 2024 (Breaking it down one bite at a time)Packaging the Monolith - PHP Tek 2024 (Breaking it down one bite at a time)
Packaging the Monolith - PHP Tek 2024 (Breaking it down one bite at a time)Dana Luther
 
办理(UofR毕业证书)罗切斯特大学毕业证成绩单原版一比一
办理(UofR毕业证书)罗切斯特大学毕业证成绩单原版一比一办理(UofR毕业证书)罗切斯特大学毕业证成绩单原版一比一
办理(UofR毕业证书)罗切斯特大学毕业证成绩单原版一比一z xss
 
Call Girls In The Ocean Pearl Retreat Hotel New Delhi 9873777170
Call Girls In The Ocean Pearl Retreat Hotel New Delhi 9873777170Call Girls In The Ocean Pearl Retreat Hotel New Delhi 9873777170
Call Girls In The Ocean Pearl Retreat Hotel New Delhi 9873777170Sonam Pathan
 
Font Performance - NYC WebPerf Meetup April '24
Font Performance - NYC WebPerf Meetup April '24Font Performance - NYC WebPerf Meetup April '24
Font Performance - NYC WebPerf Meetup April '24Paul Calvano
 
Blepharitis inflammation of eyelid symptoms cause everything included along w...
Blepharitis inflammation of eyelid symptoms cause everything included along w...Blepharitis inflammation of eyelid symptoms cause everything included along w...
Blepharitis inflammation of eyelid symptoms cause everything included along w...Excelmac1
 
Film cover research (1).pptxsdasdasdasdasdasa
Film cover research (1).pptxsdasdasdasdasdasaFilm cover research (1).pptxsdasdasdasdasdasa
Film cover research (1).pptxsdasdasdasdasdasa494f574xmv
 
Call Girls Service Adil Nagar 7001305949 Need escorts Service Pooja Vip
Call Girls Service Adil Nagar 7001305949 Need escorts Service Pooja VipCall Girls Service Adil Nagar 7001305949 Need escorts Service Pooja Vip
Call Girls Service Adil Nagar 7001305949 Need escorts Service Pooja VipCall Girls Lucknow
 
Git and Github workshop GDSC MLRITM
Git and Github  workshop GDSC MLRITMGit and Github  workshop GDSC MLRITM
Git and Github workshop GDSC MLRITMgdsc13
 
定制(Lincoln毕业证书)新西兰林肯大学毕业证成绩单原版一比一
定制(Lincoln毕业证书)新西兰林肯大学毕业证成绩单原版一比一定制(Lincoln毕业证书)新西兰林肯大学毕业证成绩单原版一比一
定制(Lincoln毕业证书)新西兰林肯大学毕业证成绩单原版一比一Fs
 
定制(Management毕业证书)新加坡管理大学毕业证成绩单原版一比一
定制(Management毕业证书)新加坡管理大学毕业证成绩单原版一比一定制(Management毕业证书)新加坡管理大学毕业证成绩单原版一比一
定制(Management毕业证书)新加坡管理大学毕业证成绩单原版一比一Fs
 
办理多伦多大学毕业证成绩单|购买加拿大UTSG文凭证书
办理多伦多大学毕业证成绩单|购买加拿大UTSG文凭证书办理多伦多大学毕业证成绩单|购买加拿大UTSG文凭证书
办理多伦多大学毕业证成绩单|购买加拿大UTSG文凭证书zdzoqco
 
PHP-based rendering of TYPO3 Documentation
PHP-based rendering of TYPO3 DocumentationPHP-based rendering of TYPO3 Documentation
PHP-based rendering of TYPO3 DocumentationLinaWolf1
 

Recently uploaded (20)

Top 10 Interactive Website Design Trends in 2024.pptx
Top 10 Interactive Website Design Trends in 2024.pptxTop 10 Interactive Website Design Trends in 2024.pptx
Top 10 Interactive Website Design Trends in 2024.pptx
 
Hot Sexy call girls in Rk Puram 🔝 9953056974 🔝 Delhi escort Service
Hot Sexy call girls in  Rk Puram 🔝 9953056974 🔝 Delhi escort ServiceHot Sexy call girls in  Rk Puram 🔝 9953056974 🔝 Delhi escort Service
Hot Sexy call girls in Rk Puram 🔝 9953056974 🔝 Delhi escort Service
 
定制(UAL学位证)英国伦敦艺术大学毕业证成绩单原版一比一
定制(UAL学位证)英国伦敦艺术大学毕业证成绩单原版一比一定制(UAL学位证)英国伦敦艺术大学毕业证成绩单原版一比一
定制(UAL学位证)英国伦敦艺术大学毕业证成绩单原版一比一
 
A Good Girl's Guide to Murder (A Good Girl's Guide to Murder, #1)
A Good Girl's Guide to Murder (A Good Girl's Guide to Murder, #1)A Good Girl's Guide to Murder (A Good Girl's Guide to Murder, #1)
A Good Girl's Guide to Murder (A Good Girl's Guide to Murder, #1)
 
Magic exist by Marta Loveguard - presentation.pptx
Magic exist by Marta Loveguard - presentation.pptxMagic exist by Marta Loveguard - presentation.pptx
Magic exist by Marta Loveguard - presentation.pptx
 
Model Call Girl in Jamuna Vihar Delhi reach out to us at 🔝9953056974🔝
Model Call Girl in  Jamuna Vihar Delhi reach out to us at 🔝9953056974🔝Model Call Girl in  Jamuna Vihar Delhi reach out to us at 🔝9953056974🔝
Model Call Girl in Jamuna Vihar Delhi reach out to us at 🔝9953056974🔝
 
Call Girls South Delhi Delhi reach out to us at ☎ 9711199012
Call Girls South Delhi Delhi reach out to us at ☎ 9711199012Call Girls South Delhi Delhi reach out to us at ☎ 9711199012
Call Girls South Delhi Delhi reach out to us at ☎ 9711199012
 
Packaging the Monolith - PHP Tek 2024 (Breaking it down one bite at a time)
Packaging the Monolith - PHP Tek 2024 (Breaking it down one bite at a time)Packaging the Monolith - PHP Tek 2024 (Breaking it down one bite at a time)
Packaging the Monolith - PHP Tek 2024 (Breaking it down one bite at a time)
 
办理(UofR毕业证书)罗切斯特大学毕业证成绩单原版一比一
办理(UofR毕业证书)罗切斯特大学毕业证成绩单原版一比一办理(UofR毕业证书)罗切斯特大学毕业证成绩单原版一比一
办理(UofR毕业证书)罗切斯特大学毕业证成绩单原版一比一
 
Call Girls In The Ocean Pearl Retreat Hotel New Delhi 9873777170
Call Girls In The Ocean Pearl Retreat Hotel New Delhi 9873777170Call Girls In The Ocean Pearl Retreat Hotel New Delhi 9873777170
Call Girls In The Ocean Pearl Retreat Hotel New Delhi 9873777170
 
Font Performance - NYC WebPerf Meetup April '24
Font Performance - NYC WebPerf Meetup April '24Font Performance - NYC WebPerf Meetup April '24
Font Performance - NYC WebPerf Meetup April '24
 
Blepharitis inflammation of eyelid symptoms cause everything included along w...
Blepharitis inflammation of eyelid symptoms cause everything included along w...Blepharitis inflammation of eyelid symptoms cause everything included along w...
Blepharitis inflammation of eyelid symptoms cause everything included along w...
 
Film cover research (1).pptxsdasdasdasdasdasa
Film cover research (1).pptxsdasdasdasdasdasaFilm cover research (1).pptxsdasdasdasdasdasa
Film cover research (1).pptxsdasdasdasdasdasa
 
Call Girls Service Adil Nagar 7001305949 Need escorts Service Pooja Vip
Call Girls Service Adil Nagar 7001305949 Need escorts Service Pooja VipCall Girls Service Adil Nagar 7001305949 Need escorts Service Pooja Vip
Call Girls Service Adil Nagar 7001305949 Need escorts Service Pooja Vip
 
Git and Github workshop GDSC MLRITM
Git and Github  workshop GDSC MLRITMGit and Github  workshop GDSC MLRITM
Git and Github workshop GDSC MLRITM
 
定制(Lincoln毕业证书)新西兰林肯大学毕业证成绩单原版一比一
定制(Lincoln毕业证书)新西兰林肯大学毕业证成绩单原版一比一定制(Lincoln毕业证书)新西兰林肯大学毕业证成绩单原版一比一
定制(Lincoln毕业证书)新西兰林肯大学毕业证成绩单原版一比一
 
定制(Management毕业证书)新加坡管理大学毕业证成绩单原版一比一
定制(Management毕业证书)新加坡管理大学毕业证成绩单原版一比一定制(Management毕业证书)新加坡管理大学毕业证成绩单原版一比一
定制(Management毕业证书)新加坡管理大学毕业证成绩单原版一比一
 
办理多伦多大学毕业证成绩单|购买加拿大UTSG文凭证书
办理多伦多大学毕业证成绩单|购买加拿大UTSG文凭证书办理多伦多大学毕业证成绩单|购买加拿大UTSG文凭证书
办理多伦多大学毕业证成绩单|购买加拿大UTSG文凭证书
 
young call girls in Uttam Nagar🔝 9953056974 🔝 Delhi escort Service
young call girls in Uttam Nagar🔝 9953056974 🔝 Delhi escort Serviceyoung call girls in Uttam Nagar🔝 9953056974 🔝 Delhi escort Service
young call girls in Uttam Nagar🔝 9953056974 🔝 Delhi escort Service
 
PHP-based rendering of TYPO3 Documentation
PHP-based rendering of TYPO3 DocumentationPHP-based rendering of TYPO3 Documentation
PHP-based rendering of TYPO3 Documentation
 

02slidLarge value of face area Large value of face area

  • 1. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 1 Chapter 2 Elementary Programming
  • 2. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 2 Motivations In the preceding chapter, you learned how to create, compile, and run a Java program. Starting from this chapter, you will learn how to solve practical problems programmatically. Through these problems, you will learn Java primitive data types and related subjects, such as variables, constants, data types, operators, expressions, and input and output.
  • 3. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 3 Objectives  To write Java programs to perform simple computations (§2.2).  To obtain input from the console using the Scanner class (§2.3).  To use identifiers to name variables, constants, methods, and classes (§2.4).  To use variables to store data (§§2.5–2.6).  To program with assignment statements and assignment expressions (§2.6).  To use constants to store permanent data (§2.7).  To name classes, methods, variables, and constants by following their naming conventions (§2.8).  To explore Java numeric primitive data types: byte, short, int, long, float, and double (§2.9.1).  To perform operations using operators +, -, *, /, and % (§2.9.2).  To perform exponent operations using Math.pow(a, b) (§2.9.3).  To write integer literals, floating-point literals, and literals in scientific notation (§2.10).  To write and evaluate numeric expressions (§2.11).  To obtain the current system time using System.currentTimeMillis() (§2.12).  To use augmented assignment operators (§2.13).  To distinguish between postincrement and preincrement and between postdecrement and predecrement (§2.14).  To cast the value of one type to another type (§2.15).  To describe the software development process and apply it to develop the loan payment program (§2.16).  To represent characters using the char type (§2.17).  To represent a string using the String type (§2.18).  To obtain input using the JOptionPane input dialog boxes (§2.19).
  • 4. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 4 Introducing Programming with an Example Listing 2.1 Computing the Area of a Circle This program computes the area of the circle. ComputeArea Run IMPORTANT NOTE: (1) To enable the buttons, you must download the entire slide file slide.zip and unzip the files into a directory (e.g., c:slide) . (2) You must have installed JDK and set JDK’s bin directory in your environment path (e.g., c:Program Filesjavajdk1.7.0bin in your environment path. (3) If you are using Office 2010, check PowerPoint2010.doc located in the same folder with this ppt file.
  • 5. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 5 Trace a Program Execution public class ComputeArea { /** Main method */ public static void main(String[] args) { double radius; double area; // Assign a radius radius = 20; // Compute area area = radius * radius * 3.14159; // Display results System.out.println("The area for the circle of radius " + radius + " is " + area); } } no value radius allocate memory for radius animation
  • 6. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 6 Trace a Program Execution public class ComputeArea { /** Main method */ public static void main(String[] args) { double radius; double area; // Assign a radius radius = 20; // Compute area area = radius * radius * 3.14159; // Display results System.out.println("The area for the circle of radius " + radius + " is " + area); } } no value radius memory no value area allocate memory for area animation
  • 7. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 7 Trace a Program Execution public class ComputeArea { /** Main method */ public static void main(String[] args) { double radius; double area; // Assign a radius radius = 20; // Compute area area = radius * radius * 3.14159; // Display results System.out.println("The area for the circle of radius " + radius + " is " + area); } } 20 radius no value area assign 20 to radius animation
  • 8. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 8 Trace a Program Execution public class ComputeArea { /** Main method */ public static void main(String[] args) { double radius; double area; // Assign a radius radius = 20; // Compute area area = radius * radius * 3.14159; // Display results System.out.println("The area for the circle of radius " + radius + " is " + area); } } 20 radius memory 1256.636 area compute area and assign it to variable area animation
  • 9. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 9 Trace a Program Execution public class ComputeArea { /** Main method */ public static void main(String[] args) { double radius; double area; // Assign a radius radius = 20; // Compute area area = radius * radius * 3.14159; // Display results System.out.println("The area for the circle of radius " + radius + " is " + area); } } 20 radius memory 1256.636 area print a message to the console animation
  • 10. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 10 Reading Input from the Console 1. Create a Scanner object Scanner input = new Scanner(System.in); 2. Use the methods next(), nextByte(), nextShort(), nextInt(), nextLong(), nextFloat(), nextDouble(), or nextBoolean() to obtain to a string, byte, short, int, long, float, double, or boolean value. For example, System.out.print("Enter a double value: "); Scanner input = new Scanner(System.in); double d = input.nextDouble(); ComputeAreaWithConsoleInput Run ComputeAverage Run
  • 11. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 11 Identifiers  An identifier is a sequence of characters that consist of letters, digits, underscores (_), and dollar signs ($).  An identifier must start with a letter, an underscore (_), or a dollar sign ($). It cannot start with a digit. – An identifier cannot be a reserved word. (See Appendix A, “Java Keywords,” for a list of reserved words).  An identifier cannot be true, false, or null.  An identifier can be of any length.
  • 12. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 12 Variables // Compute the first area radius = 1.0; area = radius * radius * 3.14159; System.out.println("The area is “ + area + " for radius "+radius); // Compute the second area radius = 2.0; area = radius * radius * 3.14159; System.out.println("The area is “ + area + " for radius "+radius);
  • 13. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 13 Declaring Variables int x; // Declare x to be an // integer variable; double radius; // Declare radius to // be a double variable; char a; // Declare a to be a // character variable;
  • 14. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 14 Assignment Statements x = 1; // Assign 1 to x; radius = 1.0; // Assign 1.0 to radius; a = 'A'; // Assign 'A' to a;
  • 15. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 15 Declaring and Initializing in One Step  int x = 1;  double d = 1.4;
  • 16. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 16 Named Constants final datatype CONSTANTNAME = VALUE; final double PI = 3.14159; final int SIZE = 3;
  • 17. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 17 Naming Conventions  Choose meaningful and descriptive names.  Variables and method names: – Use lowercase. If the name consists of several words, concatenate all in one, use lowercase for the first word, and capitalize the first letter of each subsequent word in the name. For example, the variables radius and area, and the method computeArea.
  • 18. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 18 Naming Conventions, cont.  Class names: – Capitalize the first letter of each word in the name. For example, the class name ComputeArea.  Constants: – Capitalize all letters in constants, and use underscores to connect words. For example, the constant PI and MAX_VALUE
  • 19. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 19 Numerical Data Types Name Range Storage Size byte –27 to 27 – 1 (-128 to 127) 8-bit signed short –215 to 215 – 1 (-32768 to 32767) 16-bit signed int –231 to 231 – 1 (-2147483648 to 2147483647) 32-bit signed long –263 to 263 – 1 64-bit signed (i.e., -9223372036854775808 to 9223372036854775807) float Negative range: 32-bit IEEE 754 -3.4028235E+38 to -1.4E-45 Positive range: 1.4E-45 to 3.4028235E+38 double Negative range: 64-bit IEEE 754 -1.7976931348623157E+308 to -4.9E-324 Positive range: 4.9E-324 to 1.7976931348623157E+308
  • 20. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 20 Numeric Operators Name Meaning Example Result + Addition 34 + 1 35 - Subtraction 34.0 – 0.1 33.9 * Multiplication 300 * 30 9000 / Division 1.0 / 2.0 0.5 % Remainder 20 % 3 2
  • 21. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 21 Integer Division +, -, *, /, and % 5 / 2 yields an integer 2. 5.0 / 2 yields a double value 2.5 5 % 2 yields 1 (the remainder of the division)
  • 22. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 22 Remainder Operator Remainder is very useful in programming. For example, an even number % 2 is always 0 and an odd number % 2 is always 1. So you can use this property to determine whether a number is even or odd. Suppose today is Saturday and you and your friends are going to meet in 10 days. What day is in 10 days? You can find that day is Tuesday using the following expression: Saturday is the 6th day in a week A week has 7 days After 10 days The 2nd day in a week is Tuesday (6 + 10) % 7 is 2
  • 23. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 23 Problem: Displaying Time Write a program that obtains hours and minutes from seconds. DisplayTime Run
  • 24. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 24 NOTE Calculations involving floating-point numbers are approximated because these numbers are not stored with complete accuracy. For example, System.out.println(1.0 - 0.1 - 0.1 - 0.1 - 0.1 - 0.1); displays 0.5000000000000001, not 0.5, and System.out.println(1.0 - 0.9); displays 0.09999999999999998, not 0.1. Integers are stored precisely. Therefore, calculations with integers yield a precise integer result.
  • 25. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 25 Exponent Operations System.out.println(Math.pow(2, 3)); // Displays 8.0 System.out.println(Math.pow(4, 0.5)); // Displays 2.0 System.out.println(Math.pow(2.5, 2)); // Displays 6.25 System.out.println(Math.pow(2.5, -2)); // Displays 0.16
  • 26. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 26 Number Literals A literal is a constant value that appears directly in the program. For example, 34, 1,000,000, and 5.0 are literals in the following statements: int i = 34; long x = 1000000; double d = 5.0;
  • 27. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 27 Integer Literals An integer literal can be assigned to an integer variable as long as it can fit into the variable. A compilation error would occur if the literal were too large for the variable to hold. For example, the statement byte b = 1000 would cause a compilation error, because 1000 cannot be stored in a variable of the byte type. An integer literal is assumed to be of the int type, whose value is between -231 (-2147483648) to 231–1 (2147483647). To denote an integer literal of the long type, append it with the letter L or l. L is preferred because l (lowercase L) can easily be confused with 1 (the digit one).
  • 28. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 28 Floating-Point Literals Floating-point literals are written with a decimal point. By default, a floating-point literal is treated as a double type value. For example, 5.0 is considered a double value, not a float value. You can make a number a float by appending the letter f or F, and make a number a double by appending the letter d or D. For example, you can use 100.2f or 100.2F for a float number, and 100.2d or 100.2D for a double number.
  • 29. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 29 Scientific Notation Floating-point literals can also be specified in scientific notation, for example, 1.23456e+2, same as 1.23456e2, is equivalent to 123.456, and 1.23456e-2 is equivalent to 0.0123456. E (or e) represents an exponent and it can be either in lowercase or uppercase.
  • 30. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 30 Arithmetic Expressions ) 9 4 ( 9 ) )( 5 ( 10 5 4 3 y x x x c b a y x         is translated to (3+4*x)/5 – 10*(y-5)*(a+b+c)/x + 9*(4/x + (9+x)/y)
  • 31. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 31 How to Evaluate an Expression Though Java has its own way to evaluate an expression behind the scene, the result of a Java expression and its corresponding arithmetic expression are the same. Therefore, you can safely apply the arithmetic rule for evaluating a Java expression. 3 + 4 * 4 + 5 * (4 + 3) - 1 3 + 4 * 4 + 5 * 7 – 1 3 + 16 + 5 * 7 – 1 3 + 16 + 35 – 1 19 + 35 – 1 54 - 1 53 (1) inside parentheses first (2) multiplication (3) multiplication (4) addition (6) subtraction (5) addition
  • 32. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 32 Problem: Converting Temperatures Write a program that converts a Fahrenheit degree to Celsius using the formula: FahrenheitToCelsius Run ) 32 )( (9 5   fahrenheit celsius Note: you have to write celsius = (5.0 / 9) * (fahrenheit – 32)
  • 33. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 33 Problem: Displaying Current Time Write a program that displays current time in GMT in the format hour:minute:second such as 1:45:19. The currentTimeMillis method in the System class returns the current time in milliseconds since the midnight, January 1, 1970 GMT. (1970 was the year when the Unix operating system was formally introduced.) You can use this method to obtain the current time, and then compute the current second, minute, and hour as follows. ShowCurrentTime Run Elapsed time Unix Epoch 01-01-1970 00:00:00 GMT Current Time Time System.currentTimeMills()
  • 34. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 34 Shortcut Assignment Operators Operator Example Equivalent += i += 8 i = i + 8 -= f -= 8.0 f = f - 8.0 *= i *= 8 i = i * 8 /= i /= 8 i = i / 8 %= i %= 8 i = i % 8
  • 35. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 35 Increment and Decrement Operators Operator Name Description ++var preincrement The expression (++var) increments var by 1 and evaluates to the new value in var after the increment. var++ postincrement The expression (var++) evaluates to the original value in var and increments var by 1. --var predecrement The expression (--var) decrements var by 1 and evaluates to the new value in var after the decrement. var-- postdecrement The expression (var--) evaluates to the original value in var and decrements var by 1.
  • 36. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 36 Increment and Decrement Operators, cont. int i = 10; int newNum = 10 * i++; int newNum = 10 * i; i = i + 1; Same effect as int i = 10; int newNum = 10 * (++i); i = i + 1; int newNum = 10 * i; Same effect as
  • 37. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 37 Increment and Decrement Operators, cont. Using increment and decrement operators makes expressions short, but it also makes them complex and difficult to read. Avoid using these operators in expressions that modify multiple variables, or the same variable for multiple times such as this: int k = ++i + i.
  • 38. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 38 Assignment Expressions and Assignment Statements Prior to Java 2, all the expressions can be used as statements. Since Java 2, only the following types of expressions can be statements: variable op= expression; // Where op is +, -, *, /, or % ++variable; variable++; --variable; variable--;
  • 39. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 39 Numeric Type Conversion Consider the following statements: byte i = 100; long k = i * 3 + 4; double d = i * 3.1 + k / 2;
  • 40. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 40 Conversion Rules When performing a binary operation involving two operands of different types, Java automatically converts the operand based on the following rules: 1. If one of the operands is double, the other is converted into double. 2. Otherwise, if one of the operands is float, the other is converted into float. 3. Otherwise, if one of the operands is long, the other is converted into long. 4. Otherwise, both operands are converted into int.
  • 41. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 41 Type Casting Implicit casting double d = 3; (type widening) Explicit casting int i = (int)3.0; (type narrowing) int i = (int)3.9; (Fraction part is truncated) What is wrong? int x = 5 / 2.0; byte, short, int, long, float, double range increases
  • 42. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 42 Problem: Keeping Two Digits After Decimal Points Write a program that displays the sales tax with two digits after the decimal point. SalesTax Run
  • 43. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 43 Casting in an Augmented Expression In Java, an augmented expression of the form x1 op= x2 is implemented as x1 = (T)(x1 op x2), where T is the type for x1. Therefore, the following code is correct. int sum = 0; sum += 4.5; // sum becomes 4 after this statement sum += 4.5 is equivalent to sum = (int)(sum + 4.5).
  • 44. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 44 Software Development Process Requirement Specification System Analysis System Design Testing Implementation Maintenance Deployment
  • 45. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 45 Requirement Specification Requirement Specification System Analysis System Design Testing Implementation Maintenance Deployment A formal process that seeks to understand the problem and document in detail what the software system needs to do. This phase involves close interaction between users and designers. Most of the examples in this book are simple, and their requirements are clearly stated. In the real world, however, problems are not well defined. You need to study a problem carefully to identify its requirements.
  • 46. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 46 System Analysis Requirement Specification System Analysis System Design Testing Implementation Maintenance Deployment Seeks to analyze the business process in terms of data flow, and to identify the system’s input and output. Part of the analysis entails modeling the system’s behavior. The model is intended to capture the essential elements of the system and to define services to the system.
  • 47. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 47 System Design Requirement Specification System Analysis System Design Testing Implementation Maintenance Deployment The process of designing the system’s components. This phase involves the use of many levels of abstraction to decompose the problem into manageable components, identify classes and interfaces, and establish relationships among the classes and interfaces.
  • 48. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 48 IPO Requirement Specification System Analysis System Design Input, Process, Output Testing Implementation Maintenance Deployment The essence of system analysis and design is input, process, and output. This is called IPO.
  • 49. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 49 Implementation Requirement Specification System Analysis System Design Testing Implementation Maintenance Deployment The process of translating the system design into programs. Separate programs are written for each component and put to work together. This phase requires the use of a programming language like Java. The implementation involves coding, testing, and debugging.
  • 50. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 50 Testing Requirement Specification System Analysis System Design Testing Implementation Maintenance Deployment Ensures that the code meets the requirements specification and weeds out bugs. An independent team of software engineers not involved in the design and implementation of the project usually conducts such testing.
  • 51. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 51 Deployment Requirement Specification System Analysis System Design Testing Implementation Maintenance Deployment Deployment makes the project available for use. For a Java applet, this means installing it on a Web server; for a Java application, installing it on the client's computer.
  • 52. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 52 Maintenance Requirement Specification System Analysis System Design Testing Implementation Maintenance Deployment Maintenance is concerned with changing and improving the product. A software product must continue to perform and improve in a changing environment. This requires periodic upgrades of the product to fix newly discovered bugs and incorporate changes.
  • 53. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 53 Problem: Computing Loan Payments ComputeLoan Run This program lets the user enter the interest rate, number of years, and loan amount, and computes monthly payment and total payment. 12 ) 1 ( 1 1      ars numberOfYe erestRate monthlyInt erestRate monthlyInt loanAmount ment monthlyPay
  • 54. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 54 Character Data Type char letter = 'A'; (ASCII) char numChar = '4'; (ASCII) char letter = 'u0041'; (Unicode) char numChar = 'u0034'; (Unicode) Four hexadecimal digits. NOTE: The increment and decrement operators can also be used on char variables to get the next or preceding Unicode character. For example, the following statements display character b. char ch = 'a'; System.out.println(++ch);
  • 55. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 55 Unicode Format Java characters use Unicode, a 16-bit encoding scheme established by the Unicode Consortium to support the interchange, processing, and display of written texts in the world’s diverse languages. Unicode takes two bytes, preceded by u, expressed in four hexadecimal numbers that run from 'u0000' to 'uFFFF'. So, Unicode can represent 65535 + 1 characters. Unicode u03b1 u03b2 u03b3 for three Greek letters
  • 56. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 56 Problem: Displaying Unicodes Write a program that displays two Chinese characters and three Greek letters. DisplayUnicode Run
  • 57. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 57 Escape Sequences for Special Characters Description Escape Sequence Unicode Backspace b u0008 Tab t u0009 Linefeed n u000A Carriage return r u000D Backslash u005C Single Quote ' u0027 Double Quote " u0022
  • 58. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 58 Appendix B: ASCII Character Set ASCII Character Set is a subset of the Unicode from u0000 to u007f
  • 59. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 59 ASCII Character Set, cont. ASCII Character Set is a subset of the Unicode from u0000 to u007f
  • 60. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 60 Casting between char and Numeric Types int i = 'a'; // Same as int i = (int)'a'; char c = 97; // Same as char c = (char)97;
  • 61. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 61 Problem: Monetary Units This program lets the user enter the amount in decimal representing dollars and cents and output a report listing the monetary equivalent in single dollars, quarters, dimes, nickels, and pennies. Your program should report maximum number of dollars, then the maximum number of quarters, and so on, in this order. ComputeChange Run
  • 62. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 62 Trace ComputeChange int remainingAmount = (int)(amount * 100); // Find the number of one dollars int numberOfOneDollars = remainingAmount / 100; remainingAmount = remainingAmount % 100; // Find the number of quarters in the remaining amount int numberOfQuarters = remainingAmount / 25; remainingAmount = remainingAmount % 25; // Find the number of dimes in the remaining amount int numberOfDimes = remainingAmount / 10; remainingAmount = remainingAmount % 10; // Find the number of nickels in the remaining amount int numberOfNickels = remainingAmount / 5; remainingAmount = remainingAmount % 5; // Find the number of pennies in the remaining amount int numberOfPennies = remainingAmount; 1156 remainingAmount remainingAmount initialized Suppose amount is 11.56
  • 63. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 63 Trace ComputeChange int remainingAmount = (int)(amount * 100); // Find the number of one dollars int numberOfOneDollars = remainingAmount / 100; remainingAmount = remainingAmount % 100; // Find the number of quarters in the remaining amount int numberOfQuarters = remainingAmount / 25; remainingAmount = remainingAmount % 25; // Find the number of dimes in the remaining amount int numberOfDimes = remainingAmount / 10; remainingAmount = remainingAmount % 10; // Find the number of nickels in the remaining amount int numberOfNickels = remainingAmount / 5; remainingAmount = remainingAmount % 5; // Find the number of pennies in the remaining amount int numberOfPennies = remainingAmount; 1156 remainingAmount Suppose amount is 11.56 11 numberOfOneDollars numberOfOneDollars assigned animation
  • 64. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 64 Trace ComputeChange int remainingAmount = (int)(amount * 100); // Find the number of one dollars int numberOfOneDollars = remainingAmount / 100; remainingAmount = remainingAmount % 100; // Find the number of quarters in the remaining amount int numberOfQuarters = remainingAmount / 25; remainingAmount = remainingAmount % 25; // Find the number of dimes in the remaining amount int numberOfDimes = remainingAmount / 10; remainingAmount = remainingAmount % 10; // Find the number of nickels in the remaining amount int numberOfNickels = remainingAmount / 5; remainingAmount = remainingAmount % 5; // Find the number of pennies in the remaining amount int numberOfPennies = remainingAmount; 56 remainingAmount Suppose amount is 11.56 11 numberOfOneDollars remainingAmount updated animation
  • 65. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 65 Trace ComputeChange int remainingAmount = (int)(amount * 100); // Find the number of one dollars int numberOfOneDollars = remainingAmount / 100; remainingAmount = remainingAmount % 100; // Find the number of quarters in the remaining amount int numberOfQuarters = remainingAmount / 25; remainingAmount = remainingAmount % 25; // Find the number of dimes in the remaining amount int numberOfDimes = remainingAmount / 10; remainingAmount = remainingAmount % 10; // Find the number of nickels in the remaining amount int numberOfNickels = remainingAmount / 5; remainingAmount = remainingAmount % 5; // Find the number of pennies in the remaining amount int numberOfPennies = remainingAmount; 56 remainingAmount Suppose amount is 11.56 11 numberOfOneDollars 2 numberOfOneQuarters numberOfOneQuarters assigned animation
  • 66. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 66 Trace ComputeChange int remainingAmount = (int)(amount * 100); // Find the number of one dollars int numberOfOneDollars = remainingAmount / 100; remainingAmount = remainingAmount % 100; // Find the number of quarters in the remaining amount int numberOfQuarters = remainingAmount / 25; remainingAmount = remainingAmount % 25; // Find the number of dimes in the remaining amount int numberOfDimes = remainingAmount / 10; remainingAmount = remainingAmount % 10; // Find the number of nickels in the remaining amount int numberOfNickels = remainingAmount / 5; remainingAmount = remainingAmount % 5; // Find the number of pennies in the remaining amount int numberOfPennies = remainingAmount; 6 remainingAmount Suppose amount is 11.56 11 numberOfOneDollars 2 numberOfQuarters remainingAmount updated animation
  • 67. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 67 The String Type The char type only represents one character. To represent a string of characters, use the data type called String. For example, String message = "Welcome to Java"; String is actually a predefined class in the Java library just like the System class and JOptionPane class. The String type is not a primitive type. It is known as a reference type. Any Java class can be used as a reference type for a variable. Reference data types will be thoroughly discussed in Chapter 8, “Objects and Classes.” For the time being, you just need to know how to declare a String variable, how to assign a string to the variable, and how to concatenate strings.
  • 68. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 68 String Concatenation // Three strings are concatenated String message = "Welcome " + "to " + "Java"; // String Chapter is concatenated with number 2 String s = "Chapter" + 2; // s becomes Chapter2 // String Supplement is concatenated with character B String s1 = "Supplement" + 'B'; // s1 becomes SupplementB
  • 69. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 69 Debugging Logic errors are called bugs. The process of finding and correcting errors is called debugging. A common approach to debugging is to use a combination of methods to narrow down to the part of the program where the bug is located. You can hand-trace the program (i.e., catch errors by reading the program), or you can insert print statements in order to show the values of the variables or the execution flow of the program. This approach might work for a short, simple program. But for a large, complex program, the most effective approach for debugging is to use a debugger utility.
  • 70. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 70 Debugger Debugger is a program that facilitates debugging. You can use a debugger to Execute a single statement at a time. Trace into or stepping over a method. Set breakpoints. Display variables. Display call stack. Modify variables.
  • 71. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 71 JOptionPane Input This book provides two ways of obtaining input. 1. Using the Scanner class (console input) 2. Using JOptionPane input dialogs
  • 72. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 72 Getting Input from Input Dialog Boxes String input = JOptionPane.showInputDialog( "Enter an input");
  • 73. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 73 Getting Input from Input Dialog Boxes String string = JOptionPane.showInputDialog( null, “Prompting Message”, “Dialog Title”, JOptionPane.QUESTION_MESSAGE);
  • 74. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 74 Two Ways to Invoke the Method There are several ways to use the showInputDialog method. For the time being, you only need to know two ways to invoke it. One is to use a statement as shown in the example: String string = JOptionPane.showInputDialog(null, x, y, JOptionPane.QUESTION_MESSAGE); where x is a string for the prompting message, and y is a string for the title of the input dialog box. The other is to use a statement like this: JOptionPane.showInputDialog(x); where x is a string for the prompting message.
  • 75. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 75 Converting Strings to Integers The input returned from the input dialog box is a string. If you enter a numeric value such as 123, it returns “123”. To obtain the input as a number, you have to convert a string into a number. To convert a string into an int value, you can use the static parseInt method in the Integer class as follows: int intValue = Integer.parseInt(intString); where intString is a numeric string such as “123”.
  • 76. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 76 Converting Strings to Doubles To convert a string into a double value, you can use the static parseDouble method in the Double class as follows: double doubleValue =Double.parseDouble(doubleString); where doubleString is a numeric string such as “123.45”.
  • 77. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 77 Problem: Computing Loan Payments Using Input Dialogs ComputeLoanUsingInputDialog Run Same as the preceding program for computing loan payments, except that the input is entered from the input dialogs and the output is displayed in an output dialog. 12 ) 1 ( 1 1     ars numberOfYe erestRate monthlyInt erestRate monthlyInt loanAmount
  • 78. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 78 Debugging in NetBeans Supplement II.E, Learning Java Effectively with NetBeans Companion Website
  • 79. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. Liang, Introduction to Java Programming, Ninth Edition, (c) 2013 Pearson Education, Inc. All rights reserved. 79 Debugging in Eclipse Supplement II.G, Learning Java Effectively with NetBeans Companion Website