冒泡排序

var arr = [21, 434, 11, 333, 75, 39, 90, 234, 66, 85];

for(var i = 0; i < arr.length - 1; ++i) {
  for(var u = 0; u < arr.length - 1 - i; ++u) {
    if(arr[u] > arr[u + 1]) {
      var temp = arr[u + 1];
      arr[u + 1] = arr[u];
      arr[u] = temp;
    }
  }
}
console.log(arr);