what does $.functionName(); mean in javascript?

Question

I am not familiar with this syntax. What does the $. mean before the function call?

Are you using jQuery? In this case it's just a shortcut for the jQuery() function. — Adriano Repetti, Apr 26 '12 at 11:00
possible duplicate of [Can someone explain the dollar sign in Javascript?](http://stackoverflow.com/questions/846585/can-someone-explain-the-dollar-sign-in-javascript) — Greg Bacon, Apr 26 '12 at 12:14

score 7 · Accepted Answer · answered Apr 26 '12 at 11:02

7

$ is just a name of some object. It could be jQuery, or Prototype, in case you're using one of these libraries.

So $.functionName() simply stands for calling a function named functionName of the object named $.

answered Apr 26 '12 at 11:02

Dmytro Shevchenko

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thanks for your comment. But which object would $ be? How do I know which object it is? – user840930 Apr 26 '12 at 11:05
@user840930 look at what javascript libraries are used on the page. First of all, look in the page source code and find all ` – Dmytro Shevchenko Apr 26 '12 at 11:07
I see. Thank you and everyone else for all the replies! – user840930 Apr 26 '12 at 11:18

score 3 · Answer 2 · answered Apr 26 '12 at 11:02

3

Over here $ sign can be replaced with "jQuery " keyword.

$.functionName();

is the same as

jQuery.functionName();

if you are using jQuery framework. If using something else, it may refer to base object as in jQuery.

answered Apr 26 '12 at 11:02

SadullahCeran

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score 2 · Answer 3 · answered Apr 26 '12 at 11:02

2

The dollar sign function has become the more-or-less de facto shortcut to document.getElementById().

http://osric.com/chris/accidental-developer/2008/04/the-javascript-dollar-sign-function/ Check this

And is used by Jquery, Mootools or any other javascript frameworks. Even you can make one

This is a small example

function $(obj) {
    return document.getElementById(obj);
}

answered Apr 26 '12 at 11:02

themhz

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"De facto" standards should burn in hell. I've had enough fun watching people complain about Chrome breaking "de facto" properties order that "de jure" was always undefined. – Oleg V. Volkov Apr 26 '12 at 11:05
true, but its not the "De facto" problem, it's the browsers w3c implementation on html,javascript,css, the problem. – themhz Apr 26 '12 at 11:09
But before 3 years, the task of browsers keeping the "De facto standards" was worse. Now days things are much more better. – themhz Apr 26 '12 at 11:11

score 1 · Answer 4 · answered Apr 26 '12 at 11:03

$ - is just an object name, since $ is valid symbol in JavaScript identifiers. This is not some special syntax, just a regular retrieving of 'functionName' property from object and calling it. Some libraries (like jQuery, for example) alias their main object to this short name to make calls take less space.

score 0 · Answer 5 · answered Apr 26 '12 at 11:00

0

This is alias for JQuery object or Prototype or MooTools. Also you can see _. - Underscore.

answered Apr 26 '12 at 11:00

Denis Ermolin

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what does $.functionName(); mean in javascript?

5 Answers5