Why does accessing an element in an object using an array as a key work?

Question

What do you make of this?

var x = {a: 1};         //=> {a: 1}
var y = Object.keys(x); //=> [\'a\']
x[y]                    //=> 1

Answer 1

@Quentin suggests that property names are automatically converted to strings. Ok, I think he's onto something there, but giving two explicit arr.toString() examples doesn't really demonstrate accessing the property of an object using an array. I offered this as an edit to his post. However, he rolled it back.

Anyway, this demonstrates the implicit behavior much more evidently, imo.

var x = {'a,b,c': 1};

var y = ['a','b','c'];

x[y]; //=> 1