Advanced Java Programming CSE 7345/5345/ NTU 531

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Advanced Java ProgrammingCSE 7345/5345/ NTU 531
Welcome Back!!!

• Session 2

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Chantale Laurent-Rice
Office Hours by appt 330pm-430pm SIC 353
Welcome Back!!!
trice75447_at_aol.com
claurent_at_engr.smu.edu
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Introduction

• Chapter 1
• Course Objectives
• Organization of the Book

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Objectives

• Upon completing this chapter, you will understand
  
• Create, compile, and run Java programs
• Primitive data types

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Book Chapters

• Part I Fundamentals of Programming
• Chapter 1 Introduction to Java
• Chapter 2 Primitive Data Types and Operations
• Chapter 3 Control Statements
• Chapter 4 Methods
• Chapter 5 Arrays

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Book Chapters, cont.

• Part II Object-Oriented Programming
• Chapter 6 Objects and Classes
• Chapter 7 Strings
• Chapter 8 Class Inheritance and Interfaces
• Chapter 9 Object-Oriented Software Development

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Book Chapters, cont.

• Part III GUI Programming
• Chapter 10 Getting Started with GUI Programming
• Chapter 11 Creating User Interfaces
• Chapter 12 Applets and Advanced GUI

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Book Chapters, cont.

• Part IV Developing Comprehensive Projects
• Chapter 13 Exception Handling
• Chapter 14 Internationalization
• Chapter 15 Multithreading
• Chapter 16 Multimedia
• Chapter 17 Input and Output
• Chapter 18 Networking
• Chapter 19 Java Data Structures

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Chapter 1

• Objectives
• Get an overall perspective of what capabilities
  and features are encompassed by Java and its
  development kit.
• Take a first look at Java syntax.
• Getting Input from Input Dialog Boxes
• Style and Documentation Guidelines

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What Is Java?

• History
• Characteristics of Java

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What is Java?

• An Object-Oriented Programming Language developed
  at Sun Microsystems
• A Virtual Machine (run-time environment) that can
  be embedded in web browsers (e.g. Netscape
  Navigator, Microsoft Internet Explorer and IBM
  WebExplorer) and operating systems.
• A set of standardized Class libraries (packages),
  that support
• Creating graphical user interfaces
• Communicating over networks
• Controlling multimedia data

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History

• James Gosling and Sun Microsystems
• Oak
• Java, May 20, 1995, Sun World
• HotJava
• The first Java-enabled Web browser
• JDK Evolutions
• J2SE, J2ME, and J2EE (not mentioned in the book)

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Characteristics of Java

• Java is simple
• Object-Oriented
• Distributed
• Interpreted
• Robust

• Secure
• Architecture-neutral
• Portable
• High-performance
• Multithreaded
• dynamic

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Java is Simple

• Java is not just a language for use with the
  Internet.
• It is a full featured Object-Oriented Programming
  Language (OOPL).
• Java is a bit easier than the popular OOP
  language C.
• Java uses automatic memory allocation and garbage
  collection.

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What is Object-Oriented Programming?

• Think of OOP as a set of implementation
  techniques that
• Can be done in any programming language
• Are very difficult to do in most programming
  languages
• OOP provides great flexibility, modularity, and
  reusability.

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Java is Distributed

• Distributed computing involves several computers
  working together on a network.
• Javas concurrency features make is unique for
  developing many interactive and networked
  applications.

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Java is Interpreted

• Java Virtual Machine
• Java is compiled to byte-codes whose target
  architecture is the Java Virtual machine (JVM).
• The virtual machine is embeddable within other
  environments, e.g. web browser and operating
  systems.
• Utilize a byte-code verifier when reading in
  byte-codes. The class loader is employed for
  classes loaded over the network (enhances
  security)

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Java Virtual Machine

• JVM

Environment
Java Source code .java
Java byte-code .class
java
Java VM
javac
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Java is Robust

• Robust means reliable.
• No programming language can ensure complete
  reliability.
• Java puts a lot of emphasis on early checking for
  possible errors, because Java compilers can
  detect many problems that would first show up at
  execution time in other languages.
• Java has a runtime exception-handling feature to
  provide programming support for robustness.

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Java Is Architecture-Neutral

• Java is interpreted.
• JIT compiler
• Just-in-time compilers
• This provides
• Improved performance
• Better match to specific hardware

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JIT Compiler

• JIT- takes byte-codes and change it to machine
  code.

J.I.T. Compiler
JVM Running Applet or Application
.class file
machine code
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JIT Compiler

• Because of the need for architecture
  independence, performance tuning must be
  performed on the client-side.
• This client-side compilation is known as
  Just-In-Time (JIT) compilation.

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Portable, Dynamic, Multithreaded, and Extensible
.class files

• Java runtime based on architecturally-neutral
  byte-codes
• (per class).
• Multithreading is a programs capability to
  perform several
• tasks simultaneously.

interpreted
Java Runtime
loaded classes (byte-codes)
call
Native .dll
Native .dll
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Advantages

• Byte-code is a compact machine language form. In
  Java the target machine is the Java Virtual
  Machine (VM).
• These byte-codes are thus portable across
  architecture boundaries.
• Applets and Applications have class files
  loaded on their behalf in order to execute.

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JDK Versions

• JDK 1.02 (1995)
• JDK 1.1 (1996)
• Java 2 SDK v 1.2 (a.k.a JDK 1.2, 1998)
• Java 2 SDK v 1.3 (a.k.a JDK 1.3, 2000)
• Java 2 SDK v 1.4 (a.k.a JDK 1.4, 2002)

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JDK Editions

• Java Standard Edition (J2SE)
• J2SE can be used to develop client-side
  standalone applications or applets.
• Java Enterprise Edition (J2EE)
• J2EE can be used to develop server-side
  applications such as Java servlets and Java
  ServerPages.
• Java Micro Edition (J2ME).
• J2ME can be used to develop applications for
  mobile devices such as cell phones.
• This book uses J2SE to introduce Java
  programming.

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Java IDE Tools

• Forte by Sun MicroSystems
• Borland JBuilder
• Microsoft Visual J
• WebGain Café
• IBM Visual Age for Java
• IBM Eclipse

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Getting Started with Java Programming

• A Simple Java Application
• Compiling Programs
• Executing Applications

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Command Line

• Example 1.1
• //This application program prints Welcome
• //to Java!
• package chapter1
• public class Welcome
• public static void main(String args)
• System.out.println("Welcome to Java!")

Run
Source
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Creating and Compiling Programs

• On command line
• javac file.java

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Executing Applications

• On command line
• java classname

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Command line Example

• javac Welcome.java
• java Welcome
• output...

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Compiling and Running a Program
Where are the files stored in the directory?
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There are three forms of comments in Java.

• 1- int i 10 // i is used as a counter
• 2- The multiline comment
• / This is a comment / 
• This form of comment may also extend over
  several lines as shown here
• /
• This is a longer comment
• that extends over
• five lines.
• /

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There are three forms of comments in Java.

• 3-  This is the documentation comment.  
• /
• This is a Java
• documentation
• comment
• /
• The advantage of documentation comments is that
  tools can extract them from source files and
  automatically generate documentation for your
  programs. The JDK has a tool named javadoc that
  performs this function.

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Package

• The second line in the program (package
  chapter1) specifies a package name, chapter1,
  for the class Welcome.
• Forte compiles the source code in Welcome.java,
  generates Welcome.class, and stores Welcome.class
  in the chapter1 folder.

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Blocks
A pair of braces in a program forms a block that
groups components of a program.
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Block Styles

• Use end-of-line style for braces.

 
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main Method

• The main method provides the control of program
  flow. The Java interpreter executes the
  application by invoking the main method.
•  
• The main method looks like this
•  
• public static void main(String args)
• // Statements

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Displaying Text in a Message Dialog Box

• you can use the showMessageDialog method in the
  JOptionPane class.
• JOptionPane is one of the many predefined
  classes in the Java system, which can be reused.

Run
Source
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The showMessageDialog Method

• JOptionPane.showMessageDialog(null, "Welcome to
  Java!",
• "Example 1.2", JOptionPane.INFORMATION_MESSAGE))
  

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A simple Java Applet

• import java.awt.
• import java.awt.event.
• import java.applet.Applet
• import java.awt.Graphics
• /
• ltapplet code"FirstApplet" width200 height200gt
• lt/appletgt
• /
• public class FirstApplet extends Applet
• public void paint(Graphics g)
• g.drawString("This is my first applet!", 20,
  100)
• See word doc for output.

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Integral Literals

• Integral literals may be expressed in decimal,
  octal, or hexadecimal.
• The default is decimal.
• To indicate octal, prefix the literal with 0
  (zero)
• To indicate hexadecimal, prefix the literal with
  0x or 0X
• the hex digits may be upper-or lowercase.

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Integral Literals

• For example
• The value twenty-eight may be expressed the
  following ways
•                 28
•                034
•                0x1c
•                0x1C
•                0X1c
•                0X1C

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Integral Literals

• By default, an integral literal is a 32-bit
  value.
• To indicate a long (64-bit) literal, append the
  suffix L to the literal expression.
• The suffix can be lowercase, but then it looks so
  much like a one that makes it confusing.

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Literals

• Literals are explicit data values that appear in
  your program.
• A literal is a value specified in the program
  source, as opposed to one determined at runtime.
  Literals can represent primitive or string
  variables, and may appear on the right side of
  assignments or in method calls. You cannot assign
  a value into a literal, so they cannot appear on
  the left of an assignment.
• For example
• int x 25

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Boolean Literals

• The only literals of boolean type are true and
  false.
• For example
•  
• 1. boolean isBig true
•  
• 2. boolean isLittle false

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char Literals

• A char literal can be expressed by enclosing the
  desired character in single quotes,
•  
• For example
•  
• char c ' w '

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Chapter 1 Topic Summary

• Java is many things
• A concurrent object-oriented programming language
• A virtual machine and Web-aware run-time
• A powerful and stable set of class libraries.

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Chapter 2Liang, Nutshell Objectives

• Introduce Programming with an Example
• Identifiers, Variables, and Constants
• Primitive Data Types
• byte, short, int, long, float, double, char,
  boolean
• Expressions
• Operators, Precedence, Associativity, Operand
  Evaluation Order , --, , /, , , -, ,
  /, , , , , , -,
• Syntax Errors, Runtime Errors, and Logic Errors

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Java Reserved Words or Keywords

• abstract default if private this
• boolean do implements protected throw
• break double import public throws
• byte else instanceof return transient
• case extends int short try
• catch final interface static void
• char finally long strictfp volatile
• class float native super while
• const for new switch
• continue goto package synchronized

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Keyword and identifiers

• An identifier is a word used by a programmer to
  name a variable, method, class, or label.
• Keywords and reserved words may not be used as
  identifiers.
• An identifier must begin with a letter, a dollar
  sign (4), or an underscore (_) subsequent
  characters may be letter, dollar signs,
  underscores, or digits.

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Examples

• foobar // legal
• BIGinterface // legal
• incomeAfterExpenses // legal
• 3_nodes5 // illegal
• !theCase // illegal

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Using Keyword

• Using a keyword as an identifier is a syntax
  error
• Keywords that are reserved, but not used, by Java
• const
• goto

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Reserved Words

• Reserved words or keywords are words that have a
  specific meaning to the compiler and cannot be
  used for other purposes in the program.
• For example, when the compiler sees the word
  class, it understands that the word after class
  is the name for the class.

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Java support eight different basic data type

• Type Description Keyword
• character 16-bit Unicode character data char
• boolean true/false values boolean
• byte 8-bit signed integer numbers byte
• short 16-bit signed integer numbers short
• integer 32-bit signed integer numbers int
• long 64-bit signed integer numbers long
• float 32-bit signed floating-point numbers float
• double 64-bit signed floating-point
  numbers double

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Primitive Data Type

• Java's Primitive C Simple data type
• data type integral floating
•        boolean char float
•          char short long
•          byte int long double
•          short
  long
•          int
  enum
•          long
  unsigned char
•          float
  unsigned short
•          double
  unsigned int
• unsigned long

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Primitive Data Types and Operations

• Type Precision Default Value
• byte 8 bits 0
• short 16 bits 0
• int 32 bits 0
• long 64 bits 0
• char 16 bits \u0000
• float 32 bits 0.0f
• double 64 bits 0.0d
• boolean - false
• obj-ref - null

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The four signed data types are

•  
• v               byte
• v             short
• v             int
• v             long

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Valid Control Character

• Valid control character are
• \b backspace
• \t horizontal tab
• \n linefeed
• \f formfeed
• \r carriage return
• \ double quote
• \ single quote
• \\ backslash
• dddd for Unicode - is 0000 to hex ffff

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Operator Precedence

• var, var--
• , - (Unary plus and minus), var,--var
• (type) Casting
• ! (Not)
• , /, (Multiplication, division, and modulus)
• , - (Binary addition and subtraction)
• lt, lt, gt, gt (Comparison or Relational)
• , ! (Equality)
• (Unconditional AND)
• (Exclusive OR)
• (Unconditional OR)
• (Conditional AND) Short-circuit AND
• (Conditional OR) Short-circuit OR
• , , -, , /, (Assignment operator)

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Bitwise Operators

• Java defines several bitwise operators which can
  be applied to the integer types,
• long, int, short, char, byte
• These operators act upon the individual bits of
  their operands.

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Bitwise Operators

• Operator Name
• Bitwise unary NOT
• Bitwise AND
• Bitwise OR
• Bitwise exclusive OR
• gtgt Shift right
• gtgtgt Shift right zero fill
• ltlt Shift left

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Bitwise Operators

• Operator Name
• Bitwise AND assignment
• Bitwise OR assignment
• Bitwise exclusive OR assignment
• gtgt Shift right assignment
• gtgtgt Shift right zero fill assignment
• ltlt Shift left assignment

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Bitwise NOT ( )

• Also called the bitwise complement, the unary NOT
  operator, ,
• Inverts all the bits of its operand.
• Example
• Number 74
• before bitwise NOT -gt 01001010
• after the NOT operator applied -gt 10110101

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Bitwise AND ( )

• Produces a 1 bit if both operands are also 1,
  otherwise a zero is produced.
• Example
• Number 74 29 -gt 8
• -gt 0 1 0 0 1 0 1 0
• -gt 0 0 0 1 1 1 0 1
• After -gt 0 0 0 0 1 000

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Bitwise OR ( )

• Combines bits such that if either of the bits in
  the operands is a 1, then the resultant bit is a
  1. A zero if both bits are zeros.
• Example
• Number 74 29 -gt 95
• -gt 0 1 0 0 1 0 1 0
• -gt 0 0 0 1 1 1 0 1
• After -gt 0 1 0 1 1 1 1 1

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Bitwise XOR ( )

• Combines bits such that if exactly one operand is
  1, then the result is 1. Otherwise, the result is
  zero.
• Example
• Number 74 29 -gt 87
• -gt 0 1 0 0 1 0 1 0
• -gt 0 0 0 1 1 1 0 1
• After -gt 0 1 0 1 0 1 1 1

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Left shift ( ltlt )Right shift ( gtgt )unsigned
right shift ( gtgtgt)

• Left shift (gtgt) shifts all of the bits in a value
  to the left a specified number of times.
• Right shift (gtgt) shifts all of the bits in a
  value to the right a specified number of times.
• Unsigned right shift (gtgtgt) automatically fills
  the high-order bits with its previous contents
  each time a shift occurs. This preserves the sign
  of the value.

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Relational or Comparisons Operators

• Operator Name
• Equal to
• ! Not equal to
• gt Greater than
• lt Less than
• gt Greater than or equal to
• lt Less than or equal to

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Relational Operators

• The relational operators determine the
  relationship that one operand has to the other
• They determine equality and ordering.
• The result of these operations is a boolean
  value.

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Boolean Logical Operators

• Operator Name
• Logical AND
• Logical OR
• Logical XOR (exclusive OR)
• Short-circuit OR
• Short-circuit AND
• ! Logical unary NOT (inverts)

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Boolean Logical Operators

• Operator Name
• AND assignment
• OR assignment
• XOR assignment
• Equal to
• ! Not equal to
• ? Ternary if-then-else

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Boolean Logical Operators

• The Boolean Logical operators operate only on
  boolean operands.
• All of the binary logical operators combine two
  boolean values to form a resultant boolean value.

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The boolean Type and Operators

• boolean lightsOn true
• boolean lightsOn false
• boolean b (1 gt 2)
• (and) (1 lt x) (x lt 100)
• (or) (lightsOn) (isDayTime)
• ! (not) !(isStopped)

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Truth Table for Operator !
Truth Table for Operator ! Operand !Operand true
false false true
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Truth Table for Operator
Operand1Operand2Operand1 Operand2 false false f
alse false true false true false false true true t
rue
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Truth Table for Operator
Operand1 Operand2 Operand1 Operand2 false false
false false true true true false true true true t
rue
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Truth Table for Operator
Operand1 Operand2 Operand1 Operand2 false false
false false true true true false true true true fa
lse
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The and Operators

• conditional AND operator
• unconditional AND operator
• conditional OR operator
• unconditional OR operator
• exp1 exp2
• (1 lt x) (x lt 100)
• (1 lt x) (x lt 100)

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The and Operators

• If x is 1, what is x after this expression?
• (x gt 1) (x lt 10)
• If x is 1, what is x after this expression?
• (1 gt x) ( 1 gt x)
• How about (1 x) (10 gt x)?
• (1 x) (10 gt x)?

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Getting Input from Input Dialog Boxes

• String string JOptionPane.showInputDialog(
• null, Prompt Message, Dialog Title,
• 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.

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Convertting 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(doubleStrin
  g)
•  
• where doubleString is a numeric string such as
  123.45.

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Read / Work With (Course Links)

• Liang, Nutshell Chapter 3-4
• Life Cycle of Applets
• List Of Basic Tags
• Try It Editor

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Chapter 3 Control Statements

• Selection Statements
• Using if and if...else
• Nested if Statements
• Using switch Statements
• Conditional Operator
• Repetition Statements
• Looping while, do-while, and for
• Nested loops
• Using break and continue

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Selection Statements

• if Statements
• switch Statements
• Conditional Operators

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Caution

• Adding a semicolon at the end of an if clause is
  a common mistake.
• if (radius gt 0)
• area radiusradiusPI
• System.out.println(
• "The area for the circle of radius "
• radius " is " area)
• This mistake is hard to find, because it is not a
  compilation error or a runtime error, it is a
  logic error.

Wrong
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switch Statements

• switch (year)
• case 7 annualInterestRate 7.25
• break
• case 15 annualInterestRate 8.50
• break
• case 30 annualInterestRate 9.0
• break
• default System.out.println(
• "Wrong number of years, enter 7, 15, or 30")

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Repetitions

• while Loops
• do-while Loops
• for Loops
• break and continue

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Chapter 4 Methods

• Introducing Methods
• Benefits of methods, Declaring Methods, and
  Calling Methods
• Passing Parameters
• Pass by Value
• Overloading Methods
• Ambiguous Invocation
• Scope of Local Variables
• Method Abstraction
• The Math Class

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Introducing Methods
Method Structure
A method is a collection of statements that are
grouped together to perform an operation.
92
Methods

• A method is essentially a set of program
  statements. It forms the fundamental unit of
  execution in Java. Each method exists as part of
  a class.
• During the execution of a program, methods may
  invoke other methods in the same or a different
  class.  
• No program code can exist outside a method, and
  no method can exist outside a class.

93
Using Methods

• For example
• public class TheMethod
• public static void main(String args)
• System.out.println(First method)

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All methods are passed by value.

• All methods are passed by value. This means that
  copies of the arguments are provided to a method.
  
•  
• Any changes to those copies are not visible
  outside the method.
• This situation changes when an array or object is
  passed as an argument.

95
call-by-value argument passing

• In this case the entire array or object is not
  actually copied.
• Instead, only a copy of the reference is
  provided.
• Therefore, any changes to the array or object are
  visible outside the method.
• However, the reference itself is passed by value.

96
call-by-value argument passing

• Method a( ) accepts three arguments
• an int
• an int array
• an object reference
• The value of these arguments are displayed
  before and after the method call.

97
call-by-value argument passing

• The key points to note are
• The change to the first argument is not visible
  to the main( ) method.
• The changes to the array and object are visible
  to the main( ) method.

98
Example

• public class CallByValue
• public static void main(String args)
• // Initializes variables
• int i 5
• int j 1, 2, 3, 4,
• StringBuffer sb new StringBuffer("abcd")
•  
• // Display variables
• display(i, j, sb)
•  
• // call method
• a(i, j, sb)
•  
• //Display variables again
• display(i, j, sb)

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Example (cont)

• public static void a(int i, int j,
  StringBuffer sb)
• i 7
• j0 11
• sb.append("fghi")
• public static void display(int i, int j,
  StringBuffer sb)
• System.out.println(i)
• for (int index 0 index lt j.length index)
• System.out.print(jindex " ")
• System.out.println(" ")
• System.out.println(sb)
•  

100
Methods that return Values.

• The return type for a method can be used in the
  Java
•  
• The return type for a method can be any type used
  in the Java programming language, which includes
  the primitive (or scalar) types int, double,
  char, and so on, as well as class type (including
  class types you create).

101
Methods that return values

• public class GettingARaise
• public static void main(String args)
• double mySalary 200.00
• System.out.println("Demonstrating some
  raises")
• predictRaise(mySalary)
• System.out.println("Demonstrating my salary "
  mySalary)
• predictRaise(400.00)
• predictRaiseGivenIncrease(600, 800)

102
Methods that return values

• public static void predictRaise(double
  moneyAmount)
• double newAmount
• newAmount moneyAmount 1.10
• System.out.println("With raise salary is "
  newAmount)
• public static void predictRaiseGivenIncrease(doub
  le moneyAmount, double percentRate)
• double newAmount
• newAmount moneyAmount (1 percentRate)
• System.out.println("With raise predicted given
  salary is " newAmount)

103
Read / Work With (Course Links)

• Liang, Nutshell Chapter 4-6
• Life Cycle of Applets
• List Of Basic Tags
• Try It Editor