View difference between Paste ID: DrbD6qss and YQjnchP8

 import 'dart:math';
 import 'dart:js';
 
 void main() {
   List<String> stringList1 = new List<String>();
   List<String> stringList2;
 
   Random rnd = new Random();
   for(int i = 0; i < 100000; ++i) {
     stringList1.add(rnd.nextInt(1000000000).toString());
   }
   stringList2 = new List<String>.from(stringList1);
 
   // First test - uses JS implementation of Quicksort
   Stopwatch sw = new Stopwatch()..start();
   stringList1.sort((String a, String b) => a.compareTo(b));
   sw.stop();
   print("Quicksort sorting is done in: ${sw.elapsed.inMilliseconds}");
 
   // Second test - let's make sure that Array.prototype.sort() is called
   sw
       ..reset()
       ..start();
   JsArray arr = new JsArray.from(stringList2);
   arr.sort((String a, String b){ a.compareTo(b); });
   List<String> sortedList = arr.toList();
   sw.stop();
   print("JS sorting is done in: ${sw.elapsed.inMilliseconds}");
 }
 
 /*
-Results:
+Dart 1.7.2 - "unchecked" mode
 Results (3 runs, with Quicksort/Array.sort format):
 Chrome 38: 89/155, 144/156, 100/168
 FX 33: 225/354, 228/349, 225/369
 IE 11: 1028/1435, 1028/1415, 1111/1422
 
 Interesting: Array.prototype.sort seems to be slower for this case
 */