Extending built in objects
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The document discusses extending built-in objects in JavaScript by modifying their prototypes. It explains that functions have prototypes that can be used to add properties and methods, and that these properties and methods will be available to any objects created with that function. Examples are given of adding a property to the prototype of a constructor function A, and then accessing that property from an object B created with A. The document also shows how a method can be added to the Array prototype to allow printing the contents of any array.
![Array.prototype.printMe = printme;
function printme(){
for(var i=0;i<this.length;i++)
console.log(this[i]);
}](https://image.slidesharecdn.com/extendingbuilt-inobjects-150317132558-conversion-gate01/85/Extending-built-in-objects-8-320.jpg)
Extending built in objects
- 3. Prototypes
- 5. Function A(){} A.prototype.x = 27; A X : 27
- 6. Function A(){} A.prototype.x = 27; var B = new A; A X : 27 B
- 7. Function A(){} A.prototype.x = 27; var B = new A; B.name = “Ahmed Murtaza”; A X : 27 B name : “Ahmed Murtaza”
- 8. Array.prototype.printMe = printme; function printme(){ for(var i=0;i<this.length;i++) console.log(this[i]); }
- 9. Where our printMe method should live printMe