How can I extend Array.prototype.push()?

Question

I'm trying to extend the Array.push method so that using push will trigger a callback method and then perform the normal array function.

I'm not quite sure how to do this, but here's some code I've been playing with unsuccessfully.

arr = []; arr.push = function(data){      //callback method goes here      this = Array.push(data);     return this.length; }  arr.push('test'); 

Answer 1

Since push allows more than one element to be pushed, I use the arguments variable below to let the real push method have all arguments.

This solution only affects the arr variable:

arr.push = function () {     //Do what you want here...     return Array.prototype.push.apply(this, arguments); } 

This solution affects all arrays. I do not recommend that you do that.

Array.prototype.push = (function() {     var original = Array.prototype.push;     return function() {         //Do what you want here.         return original.apply(this, arguments);     }; })();