CODEWITHSUNDEEP
jquery
Marin Horvat
Marin Horvat

Reputation: 79

Difference between variables in jQuery

Can anyone tell me what is the difference between variables $variable and $.Variable in jQuery? For examle:

$x='3';
$.y(parseInt($(this).val())

Upvotes: 3

Views: 487

Answers (3)

Mike Trpcic
Mike Trpcic

Reputation: 25679

In JavaScript, you can have variable names contain the character $. If you create a new HTML document with a script tag, you can just do:

var $test = 10;
console.log($test);

And it will log 10 to the console.

jQuery uses the $ variable as a shorthand to itself, and any jQuery functions/extensions are available off of that object. The following might make it more clear:

// Assume you have already loaded jQuery
$ == jQuery; // true!
$.test = 10; // Assign a random property to the "jQuery Object"
console.log($.test); // print out "10"

Now, in the case of your example, $.y(), somebody has extended jQuery by adding a method named y, which can be accessed as $.y(). In many cases, as a way of keeping track of object types, if you have a variable that is a reference to a jQuery object, you prepend the variable name with dollarSign:

var header = document.getElementById("header"); //without jQuery
var $header = $("#header"); // with jQuery

The above is not a rule, and is just a convention that many people follow to keep their code clear.

Upvotes: 1

moonwave99
moonwave99

Reputation: 22820

$var is just a convention to tell that the var holds a jQuery wrapped DOM selection, e.g.:

var $form = $('#yourForm');

$.function on the other hand means that you are calling some "static" function of jQuery library, e.g. $.each(), without performing any DOM selection.

Upvotes: 3

Bas Slagter
Bas Slagter

Reputation: 9929

The first one ($x) is a variable (that in this case is assigned a value of the string 3. The second one is a function call to the function y(), which is assumably a jquery extension function. In your example this function gets an argument that contains the some integer coming from the value of something that is referenced by $(this).

Note that $x could just as easily have been var x = '3'. The assignment in your example is actually a bit weird because the $ prefix usually indicates that the variable is holding some jQuery selector result.

Upvotes: 5

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