javascript - Whyhow is everything $() based in jQuery? - Stack Overflow

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I know a bit of JavaScript, and can work fine with jQuery. I just don't get why everything is referenced from $(). My understanding is that $ is never needed in JavaScript (unlike for example PHP, where every variable is prefixed with $).

I've looked through the source code, and it doesn't really make sense. Is it just that $ is the function name (for example, it could have easily have been jQuery(), but they selected $?) I assume not, though, as I don't think $ is valid in function names in JavaScript?

I know a bit of JavaScript, and can work fine with jQuery. I just don't get why everything is referenced from $(). My understanding is that $ is never needed in JavaScript (unlike for example PHP, where every variable is prefixed with $).

I've looked through the source code, and it doesn't really make sense. Is it just that $ is the function name (for example, it could have easily have been jQuery(), but they selected $?) I assume not, though, as I don't think $ is valid in function names in JavaScript?

• javascript
• jquery

Share Improve this question Follow edited May 17, 2011 at 16:20 Peter Mortensen 31.6k2222 gold badges110110 silver badges133133 bronze badges asked Nov 2, 2009 at 5:09 apacheatyouapacheatyou 5911 bronze badge

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2 Answers 2

Sorted by: Reset to default 18

$ is just a global variable that's also a reference to the jQuery function, it's $ on purpose so it's less to type. $ is perfectly valid for a function name in ECMAScript:

function $(){}; alert(typeof $); 

Note that if you're using multiple libraries you can use function scope to avoid clashing dollar sign variables, eg:

jQuery.noConflict();
(function($){ 
    $('body').hide();
})(jQuery);

$() is the same as jQuery(). Also, $ is a valid function name.

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