Java Comments

Comments, comments and comments. They’re important part of our lives. With comments we can explain what we tried to do on our code.

In java there are 3 types of comments:

• Single line comments
• Multi line comments
• Documentation comments

Single line comments

Single line comments starts and ends in the same line. To write single line comment just type // and write your comment.

// My hello function
public void hello()
{
  // Yes, it prints hello
  System.out.println("Hello!");
}

Multi line comments

If you want to write something long or more tidy you can use multi line comments. To use it type /* and in the of your comment type */. It’s important to close your comment.

/*
  This function prints "Hello" in your console.
*/

public void hello()
{
  /*
  * Some people use it like that
  */

  System.out.println("Hello!");
}

Documentation comments

With javadoc we can generate documentation for our app. To make it proper we should add some special comments. To start documentation comment type /** and in the end close it with */. Also we have some tags available for us. TagDescriptionSyntax@authorAuthor of class@author name{@code}Displays text in code font without interpreting the text as HTML markup or nested javadoc tags.{@code text}{@docRoot}Represents the relative path to the generated document’s root directory from any generated page.{@docRoot}@deprecatedAdds a comment indicating that this API should no longer be used@deprecated deprecatedtext@exceptionAdds a throws subheading to the generated documentation with the classname and description text.@exception class-name description{@inheritDoc}Inherits a comment from the nearest inheritable class or implementable interface.Inherits a comment from the immediate surperclass.{@link}Inserts an in-line link with the visible text label that points to the documentation for the specified package, class, or member name of a referenced class.{@link package.class#member label}{@linkplain}Identical to {@link}, except the link’s label is displayed in plain text than code font.{@linkplain package.class#member label}@paramAdds a parameter with the specified parameter-name followed by the specified description to the “Parameters” section.@param parameter-name description@returnAdds a “Returns” section with the description text.@return description@seeAdds a “See Also” heading with a link or text entry that points to reference.@see reference@serialUsed in the doc comment for a default serializable field.@serial field-description@serialDataDocuments the data written by the writeObject( ) or writeExternal( ) methods.@serialData data-description@serialFieldDocuments an ObjectStreamField component.@serialField field-name field-type field-description@sinceAdds a “Since” heading with the specified since-text to the generated documentation.@since release@throwsThe @throws and @exception tags are synonyms.@throws class-name description{@value}When {@value} is used in the doc comment of a static field, it displays the value of that constant.{@value package.class#field}@versionAdds a “Version” subheading with the specified version-text to the generated docs when the -version option is used.@version version-text That’s look boring let’s see it on action.

/**
* The FindAvg program implements an application that
* simply calculates average of three integers and Prints
* the output on the screen.
*
* @author  Name
* @version 1.0
* @since   2020-11-18
*/
public class FindAvg
{
    /**
    * This method is used to find average of three integers.
    * @param numA This is the first parameter to findAvg method
    * @param numB  This is the second parameter to findAvg method
    * @param numC  This is the second parameter to findAvg method
    * @return int This returns average of numA, numB and numC.
    */
    public int findAvg(int numA, int numB, int numC)
    {
        return (numA + numB + numC)/3;
    }

    /**
    * This is the main method which makes use of findAvg method.
    * @param args Unused.
    * @return Nothing.
    */

    public static void main(String args[])
    {
        FindAvg obj = new FindAvg();
        int avg = obj.findAvg(10, 20, 30);

        System.out.println("Average of 10, 20 and 30 is :" + avg);
    }
}

References

• https://www.geeksforgeeks.org/comments-in-java/