get last element of a json object in javascript

Question

I got a json object in javascript like
var json = {\"20121207\":\"13\", \"20121211\":\"9\", \"20121213\":\"7\", \"20121219\":\"4\"};
without knowing the

Answer 1

var highest = json[ Object.keys(json).sort().pop() ];

Object.keys (ES5, shimmable) returns an array of the object's keys. We then sort them and grab the last one.

You can't ensure order in a for..in loop, so we can't completely rely on that. But as you said the keys are in ascending order, we can simply sort them.