Javascript Array product(begin, end)

Array.prototype.product = function(begin, end) {
 var total = 0;//from w w w. ja v  a2  s.  co  m

 for (var i = begin >> 0 || 0, len = end + 1 >> 0 || this.length >> 0; i < len; i++) {
  total *= +this[i] || 0;
 }

 return total;
};