Java Fundamentals

If you learn something new every day, you can teach something new every day.



Subject: Java Fundamentals

Topics:

• Verifying Java JDK installation is correct or not from command line.

• Installation of Eclipse IDE
• Creating a Simple Java Application. (Hello World Program)

 /**  
  * This class implements the HelloWorld program  
  * @author srinivas.kadiyala  
  * @version 1.0  
  *  
  */  
 public class HelloWorld {  
      /*  
       * Using comments in HelloWorld  
       */  
      public static void main(String[] args)   
      {  
           //Hello World Program  
           System.out.println("Hello World Again");  
           //Hello World Output - Spaces within the braces  
           System.out.println( "Hello World before Space in braces");  
           //Hello World Output - Spaces outside the spaces  
           System.out.println("Hello world before space outside braces") ;  
           //Hello World Output - New Line and Spaces within the braces  
           System.out.println(  
                     "Hello  World"  
                     );  
           //Commenting out the program.  
           //System.out.println("Hello World Last Time");  
      }  
 }  

• Run the program from Eclipse

• Run the Program from Command Line.

Step 1: Compilation of Java Code. - Successful.

Compiled without any errors.

Step 2: Running the Program.

Error: Could not find or load main class HelloWorld.

Tried different ways to make it correct. But after few minutes, with help of stackoverflow. Performed Step 3.

Step 3: Running the Program.

D:> java -cp . HelloWorld

-cp . means referring current classpath.

Program ran successfully and displayed the Output.