排序方法、其他常用的方法

快速排序

function fast (arr) {    if (arr.length <= 1) {        return arr    }    let left = []    let right = []    let p = arr.splice(0, 1)[0]    for (let i = 0, l = arr.length; i < l; i++) {        if (p > arr[i]) {            left.push(arr[i])        } else {            right.push(arr[i])        }    }    return [].concat(fast(left), [p], fast(right))}

冒泡排序

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

插入排序

function insert (arr) {    for (let i = 1, l = arr.length; i < l; i++) {            let temp = arr[i]        let j = i - 1        while (j >= 0 && arr[j] > temp) {            arr[j + 1] = arr[j]            j--        }        arr[j + 1] = temp    }    return arr}

选择排序

function selection (arr) {    let l = arr.length    for (let i = 0; i < l - 1; i++) {        let minIndex = i        for (let j = i; j < l; j++) {            if (arr[j] < arr[minIndex]) {                minIndex = j            }        }        let temp = arr[i]        arr[i] = arr[minIndex]        arr[minIndex] = temp    }    return arr}

经典阶乘函数

function factorial(num){    if(num<=1){        return 1;    }else{        return num*arguments.callee(num-1);    }}console.log(factorial(4));//24

函数节流

delayFunc(fn, interval) {  let _self = fn;  let timer;  let firstTime = true;  return function () {      let args = arguments;      let _me = this;      if (firstTime) {          _self.apply(_me, args);          firstTime = false;          return false;      }      if (timer) {          return false;      }      timer = setTimeout(function () {          clearTimeout(timer);          timer = null;          _self.apply(_me, args);      }, interval || 500);  };},