How to check whether multiple values exist within an Javascript array

Question

So, I\'m using Jquery and have two arrays both with multiple values and I want to check whether all the values in the first array exist in the second.

Answer 1

function containsAll(needles, haystack){ 
  for(var i = 0; i < needles.length; i++){
     if($.inArray(needles[i], haystack) == -1) return false;
  }
  return true;
}

containsAll([34, 78, 89], [78, 67, 34, 99, 56, 89]); // true
containsAll([34, 78, 89], [78, 67, 99, 56, 89]); // false
containsAll([34, 78, 89], [78, 89]); // false