js最常见的几种排序方法介绍

JS快速排序

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

JS选择排序

function selectSort(array){
  var len = array.length,
    min;
  
  for (i=0; i < len; i++){
    min = i;
    for (j=i+1; j < len; j++){
      if (array[j] < array[min]){
        min = j;
      }
    }
  
    if (i != min){
      exchange(array, i, min);
    }
  }
  
  return array;
}
function exchange(array, p1, p2){
  var temp = array[p1];
  array[p1] = array[p2];
  array[p2] = temp;
}

JS冒泡排序

function bubbleSort(array){
  var len = array.length;
  var i;
  var j;
  var stop;
 
  for (i = 0; i < len - 1; i++){
    for (j = 0, stop = len - 1 - i; j < stop; j++){
      if (array[j] > array[j + 1]){
        exchange(array, j, j + 1);
      }
    }
  }
  return array;
}
 
function exchange(array, p1, p2){
  var temp = array[p1];
  array[p1] = array[p2];
  array[p2] = temp;
}

JS插入排序

function insertSort(array) {
  var len  = array.length,
    value,
    i, 
    j; 
  for (i=0; i < len; i++) {
    value = array[i];
    for (j=i-1; j > -1 && array[j] > value; j--) {
      array[j+1] = array[j];
    }
    array[j+1] = value;
  }
  
  return array;
}

JS合并排序

function merge(left, right) {
  var result = [],
    left_index = 0,
    right_index = 0;
  
  while (left_index < left.length && right_index < right.length) {
    if (left[left_index] < right[right_index]) {
       result.push(left[left_index++]);
    } else {
       result.push(right[right_index++]);
    }
  }
   return result.concat(left.slice(left_index)).concat(right.slice(right_index));
}
 
function mergeSort(array) {
  if (array.length < 2) {
    return array;
  }
  
  var middle = Math.floor(array.length / 2),
    left = array.slice(0, middle),
    right = array.slice(middle);
  
  return merge(mergeSort(left), mergeSort(right));
}