详解JS中的快速排序与冒泡

function quickSort(arr) {
  if (arr.length <=1 ){
    return arr;
  }
  var middleIndex = Math.floor(arr.length / 2);
  var left = [];
  var right = [];
  var middle = arr.splice(middleIndex,1)[0];
  for (var i = 0; i < arr.length; i++) {
    if ( arr[i] > middle) {
      right.push(arr[i]);
    } else {
      left.push(arr[i]);
    }
  }
  return quickSort(left).concat(middle,quickSort(right));
}

function bubbleSort(arr) {
  for (var i = 0; i < arr.length - 1; i++) {
    for (var j = 0; j < arr.length -1 -i; j++) {
      if( arr[j] > arr[j+1]){
        var temp = arr[j];
        arr[j] = arr[j+1];
        arr[j+1] = temp;
      }
    }
  }
  return arr;
}