Getting key with the highest value from object

Question

I have a object like that one:

Object {a: 1, b: 2, undefined: 1} 

How can I quickly pull the largest value identifier (here: b

Answer 1

Supposing you've an Object like this:

var obj = {a: 1, b: 2, undefined: 1}

You can do this

var max = Math.max.apply(null,Object.keys(obj).map(function(x){ return obj[x] }));
console.log(Object.keys(obj).filter(function(x){ return obj[x] == max; })[0]);