Javascript Array fill(value, start = 0, end = this.length)

Array.prototype.fill = function(value, start = 0, end = this.length) {
 let arr = Array.prototype.slice.call(this);
 start < 0 && (start += this.length);
 end < 0 && (end += this.length);
 end > this.length && (end = this.length);
 for (let i = start; i < end; i++) {
  arr[i] = value;/*from   www  .  j a v  a2  s . c  o  m*/
 }
 return arr;
}