Why does the JavaScript need to start with ";" ?

Posted by TK on Stack Overflow See other posts from Stack Overflow or by TK
Published on 2010-03-20T01:33:46Z Indexed on 2010/03/20 1:41 UTC
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JavaScript

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serverside-javascript

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jQuery

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jquery-plugins

I have recently noticed that a lot of JavaScript files on the web starts with ; immediately following the comment section.

For example, this jQuery plugin's code starts with

/**
 * jQuery.ScrollTo
 * Copyright (c) 2007-2008 Ariel Flesler - aflesler(at)gmail(dot)com | http://flesler.blogspot.com
 * Dual licensed under MIT and GPL.
 * Date: 9/11/2008                                      
 .... skipping several lines for brevity...
 *
 * @desc Scroll on both axes, to different values
 * @example $('div').scrollTo( { top: 300, left:'+=200' }, { axis:'xy', offset:-20 } );
 */
;(function( $ ){

Why does the file needs to start with ;? I see this convention on server-side JavaScript files as well.

What is an advantage and disadvantage of doing this?

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