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@torgeir
Created November 29, 2011 09:17
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javascript's __proto__ and prototype explained
/**
* __proto__ and prototype
* - the __proto__ property the instance's 'parent' up the prototype chain
* - the prototype property refers what new instances of the type will have their __proto__ set to, i.e. what will be the new instance's 'parent' up the prototype chain
*/
/* Given */
function Object () {}
Object.prototype = {
__proto__: null
};
/* And */
function Function () {}
Function.prototype = {
__proto__: Object.prototype
};
/* When objects are created */
var o = new Object();
/* their __proto__ property is set to Object.prototype, to make them Objects */
o.__proto__ = Object.prototype;
/* When new functions are created */
function F () {}
/* their __proto__ property is set to Function.prototype, to make them Functions */
F.__proto__ = Function.prototype;
/* New instances of F should also be Objects, so Fs prototype refers Object.prototype as its __proto__ */
F.prototype = {
constructor: F,
__proto__ : Object.prototype
};
/* When new Fs are created */
var f = new F();
/* their __proto__ is set to F.prototype, to make them Fs */
f.__proto__ = F.prototype;
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