A different Array.prototype.fill

/*  Array.prototype.fill
    
    Can only modify an array that has a length of at least 1
    It changes ALL the values of an array to a single value.
    
    Make a betterFill method that fills an empty array
    And takes a first argument which is the length of the array
    And a second which is the values to insert
    The second should be either a single value or an array of values

*/

Array.prototype.betterFill = function(length = 1, values = 0) {
  let arr = this;
  let content = values instanceof Array ? values : [values];
  for(let i = 0; i < length; i++) {
    for(let j = 0; j < content.length; j++) {
      arr.push(content[j]);
    }
  }
  arr.length = length;
  return arr;
};

console.log([].betterFill(12, [1,2,3,4,5])); // [1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 1, 2]