Compare two Arrays Javascript - Associative

Question

I have searched on here for a quality method to compare associative arrays in javascript. The only decent solution I have found is the PHP.JS project which has some comparat

Answer 1

I really don't know if there is a nicer way to do it than the brute force approach:

function differences(a, b){
  var dif = {};
  for(key in a){ //In a and not in b
    if(!b[key]){
      dif[key] = a[key];
    }
  }
  for(key in a){ //in a and b but different values
    if(a[key] && b[key] && a[key]!=b[key]){
      //I don't know what you want in this case...
    }
  }
  for(key in b){ //in b and not in a
    if(!a[key]){
      dif[key] = b[key];
    }
  }
  return dif;
}

Also, they are objects, not arrays, and some properties will not be enumerable through for..in (like Array.length, for example), so take it into account for your application.