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    STRUCTURE OF A JAVA PROGRAM

                     The program created in the previous section contains a single class named HelloWorld which is declared
                     by using the class keyword. The curly brackets ({ }) are used to start and end the body of the class. The
                     HelloWorld class has one method named main( ). The main( ) method is declared by using three Java
                     keywords, which are public, static, and void. The main() method must look like:

                                                public static void main(String args[])
                     In the main method:

                        public means the method is accessible from outside the class.
                        static means the method belongs to the class rather than to instances of the class.

                        void means the method does not return a value.

                     The only term that you can change in the syntax of the main( ) method is the name of the parameter
                     args, which can be any valid identifier name. The array of strings (String []) will contain the command-
                     line arguments, if any, when the program is executed from the command prompt. In BlueJ, we can also
                     use main() method without any argument. The main() contains a single statement:

                                             System.out.println("Hello from Touchpad");
                     This statement is used to display the message “Hello from Touchpad” on the output screen. System.
                     out represents the standard output of the device where the program is running, and the println()
                     method displays the given string along with a line feed.

                     Notice  that  the  semicolon  at  the  end  of  the  System.out.println()  statement terminates the  line.
                     It is also known as the line terminator. The Java compiler ignores all whitespace and indenting, so
                     it is necessary to use a semicolon to denote the end of all statements in Java.

                     BASIC FUNDAMENTALS OF JAVA

                     Like other programming languages, Java also provides some fundamental concepts which are given
                     below:

                        Identifiers

                        Keywords

                        Data Types
                        Literals

                        Variables

                        Comments
                     Let us discuss these in detail.

                     Identifiers

                     An identifier is the name given to an object in a Java program. It is used to uniquely identify an object in
                     a program. For example, a class name or a method name.

                                                                                  Introduction to Programming in Java   91

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