[java] In Java what is the syntax for commenting out multiple lines?

In Java what is the syntax for commenting out multiple lines?

I want to do something like:

(comment)
LINES I WANT COMMENTED
LINES I WANT COMMENTED
LINES I WANT COMMENTED
(/comment)

This question is related to java comments

The answer is


/*
 *STUFF HERE
 */

or you can use // on every line.

Below is what is called a JavaDoc comment which allows you to use certain tags (@return, @param, etc...) for documentation purposes.

   /**
    *COMMENTED OUT STUFF HERE
    *AND HERE
    */

More information on comments and conventions can be found here.


With /**/:

/*
stuff to comment
*/

  • The simple question to your answer is already answered a lot of times:

    /*
    LINES I WANT COMMENTED
    LINES I WANT COMMENTED
    LINES I WANT COMMENTED
    */
    
  • From your question it sounds like you want to comment out a lot of code?? I would advise to use a repository(git/github) to manage your files instead of commenting out lines.

  • My last advice would be to learn about javadoc if not already familiar because documenting your code is really important.

As @kgrad says, /* */ does not nest and can cause errors. A better answer is:

// LINE *of code* I WANT COMMENTED 
// LINE *of code* I WANT COMMENTED 
// LINE *of code* I WANT COMMENTED 

Most IDEs have a single keyboard command for doing/undoing this, so there's really no reason to use the other style any more. For example: in eclipse, select the block of text and hit Ctrl+/
To undo that type of comment, use Ctrl+\

UPDATE: The Sun coding convention says that this style should not be used for block text comments:

// Using the slash-slash
// style of comment as shown
// in this paragraph of non-code text is 
// against the coding convention.

but // can be used 3 other ways:

  1. A single line comment
  2. A comment at the end of a line of code
  3. Commenting out a block of code

You could use /* begin comment and end it with */

Or you can simply use // across each line (not recommended)

/*
Here is an article you could of read that tells you all about how to comment
on multiple lines too!:

[http://java.sun.com/docs/codeconv/html/CodeConventions.doc4.html][1]
*/

/* 
Lines to be commented
*/

NB: multiline comments like this DO NOT NEST. This can be the source of errors. It is generally better to just comment every line with //. Most IDEs allow you to do this quite simply.