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POSetting prototype on object created through Object.create
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  1. POSetting prototype on object created through Object.create
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    copied!<p>I'm having some trouble figuring out how the prototype chain is set up given the following code. </p> <pre><code>var Model = { prototype: { init: function(){}, log: function(){ console.log('instance method log was called') } }, log: function(){ console.log('class method log was called') }, create: function() { var object = Object.create(this); object.parent = this; object.prototype = object.fn = Object.create(this.prototype); return object; }, init: function() { var instance = Object.create(this.prototype); instance.parent = this; instance.init.apply(instance, arguments); return instance; } } var User = Model.create(); User.log(); // 'class method log was called' // create a new method after creation Model.warn = function() { console.warn('warn was called') } User.warn() // 'warn was called' var user = User.init(); user.log(); // 'instance method log was called' </code></pre> <p>Specifically this line confuses me in the create method:</p> <pre><code>object.prototype = object.fn = Object.create(this.prototype); </code></pre> <p>I understand how the create method is creating a new object who's prototype points back to Model, but the penultimate line seems to overwrite that prototype with a new object (Model.prototype). However, it seems the original prototype is still intact, as I can add methods to Model even after creating a new object, and the new object can still access it.</p> <p>can someone shed some light on what is actually happening?</p> <p><strong>Edit</strong> - I should point out this code comes from <em>Javascript Web Applications</em> by O'reilly</p>
 

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