How to add/use comments in HTML, CSS, PHP, JS

CSS comment

Used to easily switch on and off CSS blocks and make it easier to understand them. It starts with /* and ends with */.

Example:

  /* Global Structure---------------------------------------- */
  .main {
margin:0 auto;
width:940px;
position:relative;
/*
  h2 
font-size:26px;
line-height:28px;
}
*/ 

PHP comment

There are two types of comments you can add:

1. single line comment used for quick notes about complex code or to temporarily disable a line of PHP code. You need to add // or # before the code.

Example:

//My comment goes here
#define('TABLE_HEADING_WRITABLE', 'Writable');

2. multi-line comment used to comment out large blocks of code or writing multiple line comments. You need to add /* before and */ after the code.

Example:

/*$Id$
osCommerce, Open Source E-Commerce Solutions
http://www.oscommerce.com
Copyright (c) 2010 osCommerce
Released under the GNU General Public License
  */

JavaScript comment

There are also two types of comments you can add:

1. single line comments used to comment out single lines of code and writing small notes. You need to Add  // before your code or text. All text to the right of them will be ignored till the next line. Example:

   //verify if value is in the array
     function in_array(value, array)
     {
   for (var i in array)
   if (array[i] == value)
   return true;
   return false;
   }

2. multi-line comments used to disable long segments of code. You need to add /* before your code and */ after it.
   
   Example:

/*function in_array(value, array){
for (var i in array)
	if (array[i] == value)
	return true;
        return false;}*/