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copied!<p>In JS, a function is an Object. It takes a while to get used to that, but it is true. Throw that around for a bit and the code that you see others using will make sense more. If you have seen Javascript where people are passing a function(){} as a parameter to another function, that is proof that functions are first class objects. </p> <p>Once you can wrap your head around that (it took me a while) then you need to understand that if you make a function, you can get a New instance of it. See the following code:</p> <pre><code>function FooName(){ var name; this.setName = function(n){ this.name = n; } this.getName = function(){ return this.name; } } var n1 = new FooName(); var n2 = new FooName(); n1.setName("FOO"); n2.setName("BAR"); </code></pre> <p>At this point you have two instances of the FooName method: n1 and n2. It is kind of a convention in JS to name your instantiable function with an Uppercase first letter, instead of the customer lowercase first letter. In this example, I indication that my function can be instanced by naming it FooName instead of fooName. I hope this makes sense. </p> <p>In the example above, n1 has three properties. A private name property, a public setName property, and a public getName property. Each time I instantiate a new FooName, a copy of getName and setName are going to be created. That can waste space in memory. Since the getName and setName isn't going to change, I don't need a new copy of it for each FooName instance. This is where prototypes come in. </p> <p>You can say the following, and then getName and setName will only exist once in memory, thus freeing up memory, which is a good thing. </p> <pre><code>FooName.prototype.setName = function(n){ this.name = n; } FooName.prototype.getName = function(){ return this.name; } </code></pre> <p>If you remove the getName and setName from the FooName function, then now you will have a FooName "class" that has two methods, getName and setName. </p> <p>Play with it. Let me know if you have questions. </p>

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