What does the "$" sign mean in jQuery or JavaScript?
JavascriptJqueryJavascript Problem Overview
> Possible Duplicate:
> What is the meaning of “$” sign in JavaScript
Why do we use the dollar ($) symbol in jQuery and JavaScript?
I always put a dollar in my scripts but I actuary don't know why.
For an example:
$('#Text').click(function () {
$('#Text').css('color', 'red')
});
This just changes the text colour when you click it, but it demonstrates my point.
Javascript Solutions
Solution 1 - Javascript
In JavaScript it has no special significance (no more than a or Q anyway). It is just an uninformative variable name.
In jQuery the variable is assigned a copy of the jQuery function. This function is heavily overloaded and means half a dozen different things depending on what arguments it is passed. In this particular example you are passing it a string that contains a selector, so the function means "Create a jQuery object containing the element with the id Text".
Solution 2 - Javascript
The $ is just a function. It is actually an alias for the function called jQuery, so your code can be written like this with the exact same results:
jQuery('#Text').click(function () {
jQuery('#Text').css('color', 'red');
});
Solution 3 - Javascript
In jQuery, the $ sign is just an alias to jQuery(), then an alias to a function.
This page reports:
> Basic syntax is: $(selector).action() > > - A dollar sign to define jQuery > - A (selector) to "query (or find)" HTML elements > - A jQuery action() to be performed on the element(s)
Solution 4 - Javascript
The jQuery syntax is tailor made for selecting HTML elements and perform some action on the element(s).
Basic syntax is: $(selector).action()
A dollar sign to define jQuery A (selector) to "query (or find)" HTML elements A jQuery action() to be performed on the element(s)
Solution 5 - Javascript
The $ symbol simply invokes the jQuery library's selector functionality. So $("#Text") returns the jQuery object for the Text div which can then be modified.
Solution 6 - Javascript
Additional to the jQuery thing treated in the other answers there is another meaning in JavaScript - as prefix for the RegExp properties representing matches, for example:
"test".match( /t(e)st/ );
alert( RegExp.$1 );
will alert "e"
But also here it's not "magic" but simply part of the properties name