array_intersect.js

function array_intersect() {
var sorted = Array.prototype.slice.call(arguments).sort(function(i,j){return i.length>j.length;});
var shortest = sorted[0];
return shortest.filter(function(elem){
  for (var i=sorted.length-1; i>0; i--){
    if(sorted[i].indexOf(elem)===-1){return false;}
  }
  return true;
});
}