How to prevent automatic sort of Object numeric property?

Question

Why I met this problem: I tried to solve an algorithm problem and I need to return the number which appeared most of the times in an array. Like [5,4,3,2,1,1] should return

Answer 1

I've stumbled with this issue with our normalised array which keyed with Ids> After did my research, I found out there's no way to fix using the object keys because by default the Javascript is sorting any object key with number when you iterate it.

The solution I've done and it worked for me is to put a 'sortIndex' field and used that to sort the list.