// returns true or false based on if obj is actually an object.
isObject = function(obj) {
  var type = typeof obj;
  return type === 'function' || type === 'object' && !!obj;
};

// returns a flattened array of what is passed in
function flatten(arr, newArr) {
  //Loop through the array
  for (let i = 0; i < arr.length; i++) {
    // If an object, then make a recursive call, othereise add to the array.
    if (isObject(arr[i])) {
      flatten(arr[i], newArr);
    } else {
      newArr.push(arr[i]);
    }
  }
  return newArr;
}