Iteration order of for..in loops in Javascript

Question

Suppose I have a Javascript object which is initialized

var letters = {q:0, t:0, o:0, b:0, y:0, n:0, u:0, m:0, p:0, 
               w:0, a:0, d:0, k:0, v:0,          


        

Answer 1

No, it cannot be relied upon, at least not in Firefox:

A for...in loop iterates over the properties of an object in an arbitrary order.