Documentation Comment in Java

Objective :

• How to write comments in Java?
• How to write single line comment in Java?
• How to write multi line comment in Java?
• How to write documentation comment in Java?
• What are the types of comments in Java?

Writing Comments in Java :

• Comments are the statements which are never executed (i.e. non-executable statements).
• Comments are often used to add notes between source code so that it becomes easy to understand & explain the function or operation of the corresponding part of source code.
• Java Compiler doesn’t read comments; comments are simply ignored during compilation.
• There are 3 types of comments available in Java as follows;

1. Single Line Comment
2. Multi Line Comment
3. Documentation Comment

Single Line Comment :

This comment is used whenever we need to write anything in single line.

Syntax : 

//<write comment here>

Example :

[sourcecode language=”java”]
//This is Single Line Comment.
[/sourcecode]

Multi Line Comment :

This type of comments are used whenever we want to write detailed notes (i.e. more than one line or in multiple lines)related to source code.

Syntax :

/*

<write comment here>

*/

Example :  

[sourcecode language=”java”]
/*
This
Is
The
Multi
Line
Comment
*/
[/sourcecode]

Documentation Comment :

• The documentation comment is used commonly to produce the javadoc for the respective program.
• The javadoc is generally HTML, if used in project it is a set of multiple HTML files describing each java program in the corresponding project.
• In the documentation comment we can add different notations such as author of the project or program, version, parameters required, information on results in return if any, etc.
• To add these notations, we have ‘@’ operator.  We just need to write the required notation along with the ‘@’ operator.
• Some javadoc tags are;
  1. @author – To describe the author of the project.
  2. @version – To describe the version of the project.
  3. @param – To explain the parameters required to perform respective operation.
  4. @return – To explain the return type of the project.

Syntax :

/**

*<write comment/description here>

*@author <write author name>

*@version <write version here>

*@param <write parameter here>

*@return <write return type here>

*/

Example :  

[sourcecode language=”java”]
/**
* This is Documentation Comment.
* @author Atul Palandurkar
* @version 1.0.0
*/
[/sourcecode]