Are functions valid keys for javascript object properties?

Question

I\'d like to use functions as keys in a javascript object. The following works, at least in Chrome:

var registry = {};
function Foo(){  };
function Bar(){  }         


        

Answer 1

Everything you put between square brackets is converted into a string, and this happens even if you put a function, a date, a regexp... So there, you're actually creating an object like this:

var registry = {
    "function Foo(){  }" : 42,
    "function Bar(){  }" : 43
};

This is a default behaviour, it works in IE too if you were wondering. It was actually exploited by John Resig in his famous addEvent function.