js 冒泡排序

var arr = [1, 5, 7, 2, 4, 3, 8, 6, 9];
console.log(arr);
var temp = 0;
for (var i = 0, len = arr.length; i < len - 1; i++){
     for (var j = 0; j < len - 1 - i; j++){
          if (arr[j] < arr[j+1]){
              temp = arr[j];
              arr[j] = arr[j+1];
              arr[j+1] = temp;
          }
     }
}
console.log(arr);