Given an array of integers (positive or negative) find the sub-array with the largest sum

sub-array-sum.js

var list = [
  2, -4,
  6, -9, [8, 9, -6],
  12, [45, 3, 7], -34, [7, -2]
];
 
sublists = [];
sublists_sum = [];
for (var i in list) {
  if (Object.prototype.toString.call(list[i]) == '[object Array]') {
    sublistssum = list[i].reduce(function (a, b) {
      return a + b;
    });
    sublists[sublistssum] = list[i];
    sublists_sum.push(sublistssum);
  }
}
var max_item = Math.max.apply(null, sublists_sum);
alert('sub-array with the largest sum is ' + sublists[max_item]);