code: function mul() {
          var args = [];
          for (var _i = 0; _i < arguments.length; _i++) {
              args[_i] = arguments[_i];
          }
          var mul = 1;
          if (args.length > 0) {
              args.map(function (number) {
                  if (isNumber(number)) {
                      mul *= number;
                  }
              });
          }
          else {
              return 0;
          }
          return mul;
      }
docs: Example: numbers = 1, 2, 3; return = 6