CPCS202 LAB 1 Instructor Information Uzma Hashmi Office

CPCS-202 LAB -1 Instructor Information Uzma Hashmi Office: B# 7/ R#1 -121 E-mail address: uzma_a 2001@yahoo. com Group Email Addresses Post message: cs 202 -lab@yahoogroups. com Subscribe: cs 202 -lab-subscribe@yahoogroups. com � I will use this group to communicate and all the Slides will be posted on the group after each lesson Prepared by Uzma Hashmi

Learning Outcomes of Lab-1 1. 2. 3. 4. 5. 6. 7. Installation of jdk 1. 7 and IDE ECLIPSE Understanding the IDE Writing , Running and Debugging the code Studying the structure of a Java Program Adding Comments White Spaces Identifiers Prepared by Uzma Hashmi

• In this semester we will learn JAVA • The IDE (integrated development environment)we will use will be Eclipse • The compiler is jdk(java development kit) • Now we will see how can we install both in Part A and Part B See next slides for the installation steps Prepared by Uzma Hashmi

PART A • First you need to install jdk for java language compilation • To do so we'll access this web link http: //www. oracle. com/technetwork/javase /downloads/index. html Prepared by Uzma Hashmi

Step 1: http: //www. oracle. com/technetwork/javase/downloads/ index. html • JRE (Java Runtime Environment) on your system to run Java applications and applets. To develop Java applications and applets, you need the JDK (Java Development Kit), which includes the JRE (Java Runtime Environment) on your system to run Java applications and applets. To develop Java applications and applets, you need the JDK (Java Development Kit), which Prepared by Uzma Hashmi includes the JRE

Step-2 Step-3 Prepared by Uzma Hashmi

7 Step-4 Step-6 Step-5 Step-7 Prepared by Uzma Hashmi

Step-8 Step-9 Step-10 Prepared by Uzma Hashmi

PART B- ECLIPSE-IDE http: //www. eclipse. org/downloads/ Step-1 Step-2 Prepared by Uzma Hashmi

Step-3 Extract the files and there you get the files listed below Step-4 Prepared by Uzma Hashmi

Using Eclipse • The system will prompt you for a workspace. The workspace is the place there you store your Java projects (more on workspaces later). Select a suitable (empty) directory and press Ok. Prepared by Uzma Hashmi

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Creating Java Project Select from the menu File -> New-> Java project. Prepared by Uzma Hashmi

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Creating Packages inside the work-space Prepared by Uzma Hashmi

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Another way of Running your code Debug Run Prepared by Uzma Hashmi

Use of Refactor Once you have created your file , you can change the name of the file using the refactor option Prepared by Uzma Hashmi

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Error description in Problems Prepared by Uzma Hashmi

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Structure of the program • In the Java programming language: – A program is made up of one or more classes – A class contains one or more methods – A method contains program statements • These terms will be explored in detail throughout the course • A Java application always contains a method called main, • A Java application name must be the same as the class name. Prepared by Uzma Hashmi

Java Program Structure // comments about the class public class My. Program { class header must be the same As the java program name My. Program. java class body Comments can be placed almost anywhere } Prepared by Uzma Hashmi

Java Program Structure // comments about the class public class My. Program { // comments about the method public static void main (String[] args) { method body method header } } Prepared by Uzma Hashmi 1 -30

Program. java //********************************** // Program. java Author: Lewis/Loftus // // Demonstrates the basic structure of a Java application. //********************************** public class Program { //--------------------------------// Prints a presidential quote. //--------------------------------public static void main (String[] args) { System. out. println ( "A quote by Abraham Lincoln: ” ); //System is a predefined class that provides access to the system. //out is the output stream that is connected to the console{e. g. Monitor}. //println() - Displays the String which is passed to it. } } System. out. println ( "Whatever you are, be a good one. ” ); Prepared by Uzma Hashmi

Comments • Comments in a program are called inline documentation • They should be included to explain the purpose of the program and describe processing steps • They do not affect how a program works • Java comments can take three forms: // this comment runs to the end of the line /* this comment runs to the terminating symbol, even across line breaks */ /** this is a javadoc comment Prepared by Uzma Hashmi */ 1 -32

Identifiers • Identifiers are the words a programmer uses in a program • An identifier can be made up of letters, digits, the underscore character ( _ ), and the dollar sign • Identifiers cannot begin with a digit • Java is case sensitive - Total, total, and TOTAL are different identifiers • By convention, programmers use different case styles for different types of identifiers, such as – title case for class names - Lincoln – upper case for constants – MAXIMUM – Combination(Compound Word)opt. -Camel Notation – E. g Class Name : My. Project Prepared by Uzma Hashmi 1 -33

Identifiers cont. • Often we use special identifiers called reserved words that already have a predefined meaning in the language ( such as void ) • A reserved word cannot be used in any other way Prepared by Uzma Hashmi

Reserved Words • The Java reserved words: abstract assert boolean break byte case catch char class const continue default do double else enum extends false finally float for goto if implements import instanceof interface long native new null package private protected public return short static strictfp super Prepared by Uzma Hashmi switch synchronized this throws transient true try void volatile while 1 -35

White Space • Spaces, blank lines, and tabs are called white space • White space is used to separate words and symbols in a program • Extra white space is ignored • A valid Java program can be formatted many ways • Programs should be formatted to enhance readability, using consistent indentation Prepared by Uzma Hashmi 1 -36

//************************* // Poem. java // // Prints a classic poem on four lines. //************************* public class Poem { public static void main(String[] args) { System. out. println("Roses are red"); System. out. println("Violets are blue"); System. out. println("Sugar is sweet"); System. out. println("And so are you!"); } } Prepared by Uzma Hashmi

Example for white spaces //********************************** // Lincoln 3. java Author: Lewis/Loftus // Demonstrates another valid program that is poorly formatted. //********************************** public class Lincoln 3 { public static void main ( String [] args ) { System. out. println ( "A quote by Abraham Lincoln: " ) ; System. out. println ( "Whatever you are, be a good one. " ) ; } } Prepared by Uzma Hashmi

Lab Assignment Prepared by Uzma Hashmi