javascript - What is (function($) {...}) (jQuery)? -


this question has answer here:

i javascript newbie , came following code.

(function($){      if(!document.defaultview || !document.defaultview.getcomputedstyle){         var oldcurcss = jquery.curcss;         jquery.curcss = function(elem, name, force){             if(name !== 'backgroundposition' || !elem.currentstyle || elem.currentstyle[ name ]){                 return oldcurcss.apply(this, arguments);             }             var style = elem.style;             if ( !force && style && style[ name ] ){                 return style[ name ];             }             return oldcurcss(elem, 'backgroundpositionx', force) +' '+ oldcurcss(elem, 'backgroundpositiony', force);         };     } })(jquery);

what function($) {...} (jquery)?

ps: don't quite code for... if possible please give hint on it.

it's self-executing anonoymous function called jquery argument, gets renamed $ inside function signature.

since don't know if jquery.noconflict() has been used in page (especially if writing distributable code plugins), way can use shorthand $ inside function safely.

who wrote stupid beacuse he's using jquery inside function anyway : )

it prevents variables polluting global namespace , encapsulates them making them unaccessible outside function.


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