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What is the meaning of symbol $ in jQuery?
$ versus jQuery
I am a bit new to jQuery but have done some things with it. however i have never used jQuery() function and am curious what the purpose of it is.
Are these the same?
jQuery("body") $("body") $ is an alias for jQuery. You can use one or the other.
You can deactivate the $ with jQuery.noConflict(); in case of a conflict
From the source code :
// Expose jQuery to the global object window.jQuery = window.$ = jQuery; So yes, it's the same. But you have two accesses, so that you avoid conflicts.
$ and jQuery.
To be the only answer to address the second part of your answer:
jQuery.data() requires an element as the first parameter, which dictates which element you wish to retrieve or set information for.
.data() operates on a jQuery object, and internally calls jQuery.data(), passing the element(s) contained within the jQuery object as the first parameter [source].
TLDR:
jQuery.data(document.body, 'foo', 'bar') === $(document.body).data('foo', 'bar'); 
jQuery in the API documentaion means that you access them as a static function (like $.data()/jQuery.data() or $.ajax()/jQuery.ajax()), otherwise it is a instance function, you first need to construct a new jQuery instance (with $(...) or jQuery(...)) in order to use the functions.Yes, they are the same, see here:
In the first formulation listed above, jQuery() — which can also be written as $() (...)
Here is a good explanation from jQuery forum.
$ and jQuery both point to the window.jQuery object, so they are one and the same. the reason some scripts use jQuery instead of $ is to prevent conflicts with other libraries such as prototype or different versions of jquery which both also use the $ variable.
Basicly, it's an alias. Usually it's used to avoid conflict with other libraries (Prototype for example) that uses the same $. $ is just a name - names in JavaScript can contain dollar signs, and can consist of just a dollar sign.
check out this answer or this one.
$ is the alias which can conflict
noConflict() so concept is still not on trackComplementing the answers, the .data and jQuery.data() functions are complementary, because one of the (.data) is aplyed in jQuery objects, i.e., the result of a selection operation. Example:
$( "#someId" ).data( "foo" ); And the another is more general method. Both of them are used to associate arbitrary data to DOM elements (and read the HTML5 data atribute). Take a look at the docs descriptions:
