几大经典排序算法实现：

1.排序算法介绍：

2.基本算法

2.1 冒泡排序

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

2.2 选择排序

function selectionSort(arr) {for (let i = 0; i < arr.length; i++) {let min = ifor (let j = i + 1; j < arr.length; j++) {if (arr[j] < arr[min]) {min = j}};[arr[i], arr[min]] = [arr[min], arr[i]]}return arr
}

2.3 插入排序

function insertionSort(arr) {for (let i = 1; i < arr.length; i++) {let preIndex = i - 1let current = arr[i]while (preIndex >= 0 && arr[preIndex] > current) {arr[preIndex + 1] = arr[preIndex]preIndex--}arr[preIndex + 1] = current}return arr
}

2.4 归并排序

function mergeSort(arr) {//采用自上而下的递归方法var len = arr.lengthif (len < 2) {return arr}var middle = Math.floor(len / 2),left = arr.slice(0, middle),right = arr.slice(middle)return merge(mergeSort(left), mergeSort(right))
}function merge(left, right) {var result = []while (left.length && right.length) {if (left[0] <= right[0]) {result.push(left.shift())} else {result.push(right.shift())}}while (left.length) result.push(left.shift())while (right.length) result.push(right.shift())return result
}

2.5 快速排序

function quickSort(arr) {if (arr.length <= 1) return arrlet midIndex = Math.floor(arr.length / 2)let mid = arr.splice(midIndex, 1)[0] //找出基准元素let left = []let right = []for (let i of arr) {if (i > mid) {right.push(i)} else {left.push(i)}}return [...quickSort(left), mid, ...quickSort(right)]
}

参考链接：十大经典算法排序总结对比