Smallest Common Multiple

function smallestCommons(arr) {
  //return arr;
  var min = Math.min(arr[0],arr[1]);
  var max = Math.max(arr[0],arr[1]);
  var _arr = [];
  for(var i = min; i <= max; i++){
    _arr.push(i);
  }
  var gcd = function(a,b){
    if(b){
      return gcd(b, a % b);
    }
    return a;
  };
  return _arr.reduce(function(prev,cur,index,array){
    return prev*cur/gcd(prev,cur);
  });
}


smallestCommons([1,5]);