Compare arrays as (multi-) sets

Question

I\'m looking for an efficient way to find out whether two arrays contain same amounts of equal elements (in the == sense), in any order:

foo = {         


        

Answer 1

i wasn't sure if "===" is ok, the question is a bit vauge... if so, this is quite a bit faster and simpler than some other possible ways of doing it:

function isSame(a,b){
  return a.length==b.length && 
      a.filter(function(a){ return b.indexOf(a)!==-1 }).length == b.length;
}