What object javascript function is bound to (what is its “this”)?

Question

I know that inside the function it is this.

var func = function {
    return this.f === arguments.callee; 
    // => true, if bound to some o         


        

Answer 1

Instead of binding the function func to the objects, why not try treating func as an object, that can hold obj1 and obj2 as its properties?

For example:

var func = function {
    this.object; // Could be obj1 or obj2
    return this.f === arguments.callee;
    // => true, if this.object is not null
}

var f = func;

f.object = obj1; // or func.object = obj2;

You can also write a function that handles whether or not the object is obj1 or obj2:

function g(f) {
  if (typeof(f) !== 'function') throw 'error: f should be function';

  if (f.object === obj)
    // this code will run if g(f) was called
    doSomething(f);
  if (f.object === obj2)
    // this code will run if g(f) or g(bound) was called
    doSomethingElse(f);
}

The reason is that you want to treat obj1 and obj2 as a property of the function f. However, when you bind, you are adding the function as a property of either obj1 or obj2. It's possible to bind the function to multiple objects, so it doesn't make sense to look for THE one object to which you bound the function; because you're adding the function as a subset of the object.

In this case, since you want to treat the object as a subset of the function, it might make sense to add a property into the function that can hold obj1 or obj2.