How do you remove a method from a javascript type

Question

I have a bit of javascript that runs on a 3rd party's website which requires me to temporarily add a function to the Array type, e.g.

Array.prototype.foo = function() { alert("foo's for everyone!"); }; 

I want to be a good developer and not pollute the type systems of other people's code as much as possible so once the function is no longer needed I want to remove the function again. Is this possible?

Answer 1

You can use delete, which in general is good for removing all types of properties from objects:

delete Array.prototype.foo;

Example: http://jsbin.com/iyamut
MDN Documentation: delete

Answer 2

Array.prototype.foo = undefined

or

delete Array.prototype.foo