"This" keyword in javascript & jQuery

Question

I am currently learning jQuery, and just started implementing "this" keyword. I understand what it does in jQuery, but does it have the same functionality in javascript, as a scope reference?

Possible duplicates: http://stackoverflow.com/questions/3127429/javascript-this-keyword, http://stackoverflow.com/questions/133973/how-does-this-keyword-work-within-a-javascript-object-literal — levelnis, Mar 29 '13 at 21:48
https://developer.mozilla.org/en-US/docs/JavaScript/Reference/Operators/this — undefined, Mar 29 '13 at 21:48

score 3 · Answer 1 · answered Mar 29 '13 at 21:46

3

this is not some jQuery magic, it is a JavaScript keyword.

answered Mar 29 '13 at 21:46

Niet the Dark Absol

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That's what I thought, thanks for the clarification. – FluxEngine Mar 29 '13 at 21:47
Just curious, what exactly can `this` be used for? Sometimes I try to implement it but find that it returns the wrong value/variable/element. – Albert Xing Mar 29 '13 at 21:47
while this may not be magic - i think it's pretty magical especially when var that = this; – James Daly Mar 29 '13 at 21:54

score 1 · Answer 2 · answered Mar 29 '13 at 21:56

1

Yes, this keyword in JavaScript still means the element in the current scope.

answered Mar 29 '13 at 21:56

palaѕн

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elclanrs · Answer 3 · 2013-03-29T22:05:02.930

Short explanation: this is the context of a function that can change depending on how that function is called. For example:

function myfunc() {
  console.log(this.toString());
}

myfunc(); //=> [object Window] 
myfunc.call('Hello World'); //=> Hello World

When using prototypes, this refers to the current instance. In jQuery it works something like this (very simplified):

(function(win) {

  // Constructor
  function jQuery(selector) {

  }

  // Shortcut to create news instances
  function $(selector) {
    return new jQuery(selector);
  }

  // Public methods
  jQuery.prototype = {

    // All methods 'return this' to allow chaining
    // 'this' is the jQuery instance
    method: function() {
      return this;
    }

  };

  win.$ = $; // expose to user

}(window));

So when you do this $(this) you're just creating a new jQuery instance of whatever this refers to (usually a DOM element) so you can inherit the prototype and use the public methods.

"This" keyword in javascript & jQuery

3 Answers3