Java Comments

Simple Comment Program

• Launch the Notepad or any other Text Editor and paste the following code:

   public class Comment {
   /* This is my first java program.
    * This will print 'Hello World' as the output
    * This is an example of multi-line comments.
    */
  
   public static void main(String []args) {
   // This is an example of single line comment
   /* This is also an example of single line comment. */
    System.out.println("Hello World");
    }
   }
  

• Save this file as Comment.java

Open a terminal and run the following command:

-- Windows
 javac C:\work\Comment.java

 -- Linux
 javac $HOME/work/Comment.java

It will produce .class file in work directory now execute the program

-- Windows
 java -cp C:\work\ Comment

 -- Linux
 java -cp $HOME/work/ Comment

Output Hello World

Java Documentation Comment

The documentation comment is used to create documentation API. To create documentation API, you need to use javadoc tool.

Syntax:

/** This is 
  documentation 
  comment
*/

• Example:

    /** This class provides methods to get addition and subtraction of given 2 numbers.*/
    public class Calculator {
    /** The add() method returns addition of given numbers.*/
    public static int add(int a, int b){return a+b;}
    /** The sub() method returns subtraction of given numbers.*/
    public static int sub(int a, int b){return a-b;}
    }
  

1. Compile it by javac tool: javac Calculator.java
2. Create Documentation API by javadoc tool: javadoc Calculator.java

Now, there will be HTML files created for your Calculator class in the current directory. Open the HTML files and see the explanation of Calculator class provided through documentation comment.

Continue

Proceed to Chap 1 - Programming Basics.