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    <p>You have it right that the 'this' keyword which refers to the object on which the currently executing method has been invoked. So in your first example the <code>clickHandler()</code> function is going to refer to the user object. </p> <p>Now in terms of jQuery when you are inside of a callback function 'this' is referring to the the 'DOM' element. The reason for this as i understand is that jQuery returns a object from its internal 'jQuery' code that maintains the reference to the element that was in context being the 'DOM' element using call() and apply(). I believe to maintain it. Doing so also allows you to accomplish that chaining of actions like <code>("button").click(somefunction).fadeIn()</code> for example.</p> <p>If you make your own jquery function such as <code>$.fn.somefunction = function() {...}</code> this refers to a jQuery object at this point.</p> <p>There might be a better why to accomplish this but I quickly changed your code using <code>call()</code> to make is refer to your user object.</p> <pre><code>var user = { tournament:"The Masters", data :[ {name:"T. Woods", age:37}, {name:"P. Mickelson", age:43} ], clickHandler: function () { // the use of this.data here is fine, because "this" refers to the user object, // and data is a property on the user object. this.data.forEach (function (person) { // But here inside the anonymous function (that we pass to the forEach method), //"this" no longer refers to the user object. // This inner function cannot access the outer function's "this" //Use call to make this refer to your user object that = Object.call(this, user); console.log ("What is This referring to? " + that); //[object Object] console.log (person.name + " is playing at " + that.tournament); // T. Woods is playing at undefined // P. Mickelson is playing at undefined }) } } user.clickHandler(); // What is This referring to? [object Object] </code></pre> <p>Another thing is in Javascript the <code>forEach</code> function takes a second parameter that will be used as the object to reference for 'this' so another way you could have done it. Now this refers to user object.</p> <pre><code>.... this.data.forEach (function (person) { // But here inside the anonymous function (that we pass to the forEach method), //"this" no longer refers to the user object. // This inner function cannot access the outer function's "this" //Use call to make this refer to your user object console.log ("What is This referring to? " + this); //[object Object] console.log (person.name + " is playing at " + this.tournament); // T. Woods is playing at Masters // P. Mickelson is playing at Masters //pass user as the object the second parameter }, user) } } </code></pre> <p><strong>Check out the explanation of this on the jquery site here is a link.</strong></p> <p><a href="http://learn.jquery.com/javascript-101/this-keyword/" rel="nofollow">http://learn.jquery.com/javascript-101/this-keyword/</a></p>
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