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POwhy prototype is undefined
 

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    <p>I known this has been asked hundreds of times, however, I can't seem to grasp the concept of <code>prototype</code></p> <p>Here's my sample script</p> <pre><code>var config = { writable: true, enumerable: true, configurable: true }; var defineProperty = function(obj, name, value) { config.value = value; Object.defineProperty(obj, name, config); } var man= Object.create(null); defineProperty(man, 'sex', "male"); var person = Object.create(man); person.greet = function (person) { return this.name + ': Why, hello there, ' + person + '.' } var p=Object.getPrototypeOf(person); alert(p.sex);//shows male person.prototype.age=13;//why there is a error said the prototype is undefined? I thought it supposed be man object... var child=function(){} child.prototype.color="red";//why this line doesn't show error? both child and person are an object . alert(child.prototype.color);//shows red var ch=Object.getPrototypeOf(child); alert(ch.color);//why it is undefined? it is supposed red. </code></pre> <p>Hope you can give me some helps... thanks.</p> <p><strong>Updated:</strong></p> <p>Thanks your guys kindly help, Based on Elclanrs's answer, Below is what I learned.</p> <p><code>Function</code> is the one of the build-in objects in javascript. the 3 format creation function object are equal.</p> <pre><code>var function_name = new Function(arg1, arg2, ..., argN, function_body) function function_name(arg1, arg2, ..., argN) { ... } var function_name=function(arg1, arg2, ..., argN) { ... } </code></pre> <p>So, that is why create a prototype chain we have to create a function and then call it with the new keyword .</p> <p><code>Function.prototype</code> is the reference to All the Function object <code>prototype</code>.</p> <p>Cheers</p>
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    1. COThis [post](http://stackoverflow.com/questions/1646698/what-is-the-new-keyword-in-javascript) is partly answer the question . very helpful.
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