Question

Here is code sample:

var eventStack = {};
function addEvent (fn) {
  eventStack[fn] = fn;
}
function removeEvent (fn) {
  delete eventStack[fn];
}
addEvent(alert);
addEvent(console.log);
addEvent(addEvent);

it works whatever function I define myself, but doesn’t work for console.log. Instead it’s replaced with _firebugignore.

I think there is some magic with toString property

EDIT hmng, I just run my code again, and It worked fine for console.log, previous time both key and value were replaced buy “_firebuignore”, I suppose its higgs bugson

Answer 1

Yes, there is some magic with Function.prototype.toString: It’s implementation-dependent, it only needs to return a representation of the function which is FunctionDeclaration-syntax-like. And of course it can’t return a JS function for all those environment-builtin functions (like console.log).

However, I don’t think it is a good idea to identify a function by its string representation at all. It can easily happen that two different functions end up in the same string (examples: two identical function expressions, identical function declarations in different scopes – or closures, builtin-functions (Array.prototype.toString.toString() == Function.prototype.toString.toString()).

Instead, use an Array for your eventStack and check for a function’s existance by indexOf().