Extending Object.prototype JavaScript

javascript ecmascript-5
Lime picture Lime · Jul 29, 2011 · Viewed 20k times · Source

I am not asking if this is okay:

Object.prototype.method = function(){};

This is deemed evil by pretty much everyone, considering it messes up for(var i in obj).

The Real Question

Ignoring

  • Incompetent browsers(browsers that don't support Object.defineProperty)
  • Potential for property collision or overriding

Assuming you have some incredibly useful method, is this considered wrong/unethical?

Object.defineProperty(Object.prototype, 'methodOnSteriods',{
  value: function(){ /* Makes breakfast, solves world peace, takes out trash */ },
  writable: true,
  configurable: true,
  enumerable: false
});

If you believe the above is unethical, why would they even implement the feature in the first place?

Answer

Alex Wayne picture Alex Wayne · Jul 29, 2011

I think it's fine if it works in your target environment.

Also I think prototype extension paranoia is overblown. As long as you use hasOwnProperty() like a good developer that it's all fine. Worst case, you overload that property elsewhere and lose the method. But that's your own fault if you do that.

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