Application Programming

         Application programming also referred as console based programming will be syntactically and semantically similar to ‘C’ (or) ‘C++’ programs. These application programs are executed for the MS-Dos prompt.

Structure of a Java program:

class class_name { public static void main(String args[]) { ………… body of the method; ….….…. } }

Note:

• Class: – A reserved keyword with which we create classes.
• Main: – like in languages such as C and C++, we have the main function where the program execution begins. Similarly in Java the program execution begins at the main method.
• Method: – method is nothing but the functions in C and C++. In Java we call the functions by the name Methods.

Executing a Java program:

1. Write a source code and save the code with the name of the class and the extension ” .java”.
2. Invoke the command prompt and switch to the folder where you saved source code.
3. Compile the source code using the compiler ” javac”.

   Syntax: – javac filename.java

   Note: If you get back your Dos-prompt, that itself is a conformation that there are no errors in the source code.

4. When you compile the source code the result is a byte code file with the extension ” .class”. Execute the byte code file using the Interpreter “java”. This is the Java run time system.

   Syntax: – java filename

Output statements in Java:

The output statements in Java is

1. System.out.print();
2. System.out.println();