Javascript Array humanSort()

Array.prototype.humanSort = function() {
  return this.sort(function(a, b) {
    aa = a.split(/(\d+)/);/*  w w w .j a v a2  s. com*/
    bb = b.split(/(\d+)/);

    for(var x = 0; x < Math.max(aa.length, bb.length); x++) {
      if(aa[x] != bb[x]) {
        var cmp1 = (isNaN(parseInt(aa[x],10)))? aa[x] : parseInt(aa[x],10);
        var cmp2 = (isNaN(parseInt(bb[x],10)))? bb[x] : parseInt(bb[x],10);
        if(cmp1 == undefined || cmp2 == undefined)
          return aa.length - bb.length;
        else
          return (cmp1 < cmp2) ? -1 : 1;
      }
    }
    return 0;
  });
}