Simple Program And Description

Let’s start the programming by compiling and running following small program.

class one

{

         public static void main(String args[])

        {

                 System.out.println(“Welcome to the World of JAVA!!!”);

        }

}

If you are using JDK, follow the following steps:-

1) Type above program in notepad / notepad++.

2) Save this program as one.java in bin folder of jdk folder.

3) Open command prompt.

4) Type cd source of bin folder.

5) Type javac one.java

By this step, JAVA compile that program and create one.class file in same folder where the one.java file is saved.

6) Again type java one

Above means running that .class file

You will get the output.

If you are using ECLIPSE, follow the steps below:-

1) Type above program in ECLIPSE.

2) Save that program.

3) Then click on run button or press F11.

4) The output will display below the program window

Description of above Program:-

class one { statements } :-

This is the start of the program. Keyword class represents the beginning of the class. Word after class keyword represents the name of class.

Syntax:-

                class class_name

public static void main(String args[]) :-

From this line main() method is begin. In JAVA all application execution begins by calling main() method.

                The public keyword is an access specifier, which allow programmer to control the visibility of class member.

                Static

                The void keyword tells the compiler that main() method does not return any value.

                The String args[] is passes as parameter to the main() method.  It represents the Array of arguments of type String.

System.out.println(); :-

                This statement simply prints the output on the screen. Every statement in JAVA ends with semicolon (;) except methods.

// :-

These lines use to add comment. Whatever written after this line is hidden from the compiler hence those lines doesn’t execute while compiling and running the code

/*…..*/ :-

                This block is also used to add comment.