what is implementation in programming | java implementation

 

Implementing a Java Program

Implementing of a java  application program involves a series of steps. They include:

·       Creating the program

·       Compiling the program

·       Running the program

Creating the Program

We can create a program using any text editor. Assume that we have entered the following program:

Simple program for testing 

class Test

{

public static void main(String agrs[])

{

System.out.println(“Welcome in java class”);

System.out.println(“ Learn about java  in class”);

}

}

We must save the program in a file called Test.java ensuring that the filename contains the class name properly. This file is called the source file. Note that  all java source file will have the extension java.

Note also that if a program contain multiple classes, the file name must be  the classname of the class containing the main method. 

          

• Compiling the Program- 

  To compile the program we must run the java Compiler javac, with the name of source file name in command line 

   

  javac Test.java

   

  If everything is okk, then javac compiler create the source file called Test.class containing the bytecode of the program.

  
  
  Note that the compiler automatically nae the bytecode file as
  <classname>  .class
  
  
  
  

  

  java program Compilation

  
  
  
  
  
  
  
  

• ·       Running the program-

  We need to use the Java interpreter to run a stand- along program. At the command prompt, type

  java Test

  Now the interpreter looks for main method in the program and begin execution from there. When executed, our program display the following. 

  
  

  
  

  Welcome to Java class

  Learn about java in class

  Note that we simply type “Test” at the command line and not “Test.class” or “Test.java”.