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    <p>In your example, the global object receives the <code>fn</code>. It is the <code>window</code> object in case of browsers. That is because you are <em>calling</em> the function in place (effectively constructing a new scope) without specific context. On the end, your <code>module</code> object is just a reference to the <code>window</code> (because of <code>return this;</code>).</p> <h2>What is <code>this</code>?</h2> <p>In JavaScript, <code>this</code> is the current context, the object on which the function was called that particular time. It is <strong>not</strong> the "holder" of the function. You can always "steal" the method from other objects and <code>apply</code> (literally) it to your own.</p> <p>Assume you want to slice the <code>arguments</code> object for some reason. It looks just like an array, but it is NOT an array. <code>arguments.slice(2,4)</code> does not work (assuming ECMAScript &lt; 5). What to do?</p> <pre><code>Array.prototype.slice.apply(arguments, [2,4]); </code></pre> <p>You need to <em>steal</em> the <code>slice</code> function from the Array prototype, and use if on your arguments. Inside the <code>slice</code> call, the "this" is the arguments object that particular time.</p> <h2>How to construct a valid module?</h2> <p>Your job is to <code>return</code> the module object. You do not want do mess with the context. It is not relevant, as long as you are not applying the function directly on module object.</p> <p>The easiest solution is the simplest.</p> <pre><code>var module = (function() { // do something internally, great for "private" stuff // then return the "public" interface return { doSomething: function() { // do something }, introduce: function() { console.log(this); } }; })(); module.introduce(); // Object {doSomething: function, introduce: function} module.doSomething(); </code></pre> <p><strong>The other way.</strong></p> <p>Alternatively, you could use the <code>this</code> to do your job, using the apply, if you really want to.</p> <pre><code>var module = {}; (function(){ this.doSomething = function() { // do something }; this.introduce = function() { console.log(this); }; }).apply(module); module.introduce(); // Object {doSomething: function, introduce: function} module.doSomething(); </code></pre> <p>Note this is almost equal to the "new" call.</p> <p>There are more equally valid ways to do it, but the first presented one is frequently used and very clear. Anyway, everything really depends on your code conventions.</p>
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    1. COEDIT: That was a mess - point is the `return this` at the end. | Thanks for clarifying `this`. I was reading this example: `var MyModule = (function() { var myPrivateData = 303; function myPrivateFunction() { alert('private'); } this.myPublicData = 42; this.myPublicFunction = function() { alert(this.myPublicData); } return this; })();` That is what confused me, I didn't understand how it would work. But it seems like it doesn't then.
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    2. CO@kjelelokk It looks strange. "return this;" just returns a global object, which is later assigned to the module. This is really bad if you want to have more than one module (which is the case i suppose).
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    3. COYes, I want more modules. I was refreshing ways to write modular javascript and came across that example. Seems like they forgot something in it.
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