js回调函数原理（教你判断下跌还是回调）

1、输入一个值，返回其数据类型**

function type(para) {

return Object.prototype.toString.call(para)

}

2、数组去重

function unique1(arr) {

return […new Set(arr)]

}

function unique2(arr) {

var obj = {};

return arr.filter(ele => {

if (!obj[ele]) {

obj[ele] = true;

return true;

}

})

}

function unique3(arr) {

var result = [];

arr.forEach(ele => {

if (result.indexOf(ele) == -1) {

result.push(ele)

}

})

return result;

}

3、字符串去重

String.prototype.unique = function () {

var obj = {},

str = ”,

len = this.length;

for (var i = 0; i < len; i++) {

if (!obj[this[i]]) {

str += this[i];

obj[this[i]] = true;

}

}

return str;

}

###### //去除连续的字符串

function uniq(str) {

return str.replace(/(w)1+/g, ‘$1’)

}

4、深拷贝 浅拷贝

//深克隆（深克隆不考虑函数）

function deepClone(obj, result) {

var result = result || {};

for (var prop in obj) {

if (obj.hasOwnProperty(prop)) {

if (typeof obj[prop] == ‘object’ && obj[prop] !== null) {

// 引用值(obj/array)且不为null

if (Object.prototype.toString.call(obj[prop]) == ‘[object Object]’) {

// 对象

result[prop] = {};

} else {

// 数组

result[prop] = [];

}

deepClone(obj[prop], result[prop])

} else {

// 原始值或func

result[prop] = obj[prop]

}

}

}

return result;

}

// 深浅克隆是针对引用值

function deepClone(target) {

if (typeof (target) !== ‘object’) {

return target;

}

var result;

if (Object.prototype.toString.call(target) == ‘[object Array]’) {

// 数组

result = []

} else {

// 对象

result = {};

}

for (var prop in target) {

if (target.hasOwnProperty(prop)) {

result[prop] = deepClone(target[prop])

}

}

return result;

}

// 无法复制函数

var o1 = jsON.parse(jsON.stringify(obj1));

5、reverse底层原理和扩展

// 改变原数组

Array.prototype.myReverse = function () {

var len = this.length;

for (var i = 0; i < len; i++) {

var temp = this[i];

this[i] = this[len – 1 – i];

this[len – 1 – i] = temp;

}

return this;

}

6、圣杯模式的继承

function inherit(Target, Origin) {

function F() {};

F.prototype = Origin.prototype;

Target.prototype = new F();

Target.prototype.constructor = Target;

// 最终的原型指向

Target.prop.uber = Origin.prototype;

}

7、找出字符串中第一次只出现一次的字母

String.prototype.firstAppear = function () {

var obj = {},

len = this.length;

for (var i = 0; i < len; i++) {

if (obj[this[i]]) {

obj[this[i]]++;

} else {

obj[this[i]] = 1;

}

}

for (var prop in obj) {

if (obj[prop] == 1) {

return prop;

}

}

}

8、找元素的第n级父元素

function parents(ele, n) {

while (ele && n) {

ele = ele.parentElement ? ele.parentElement : ele.parentNode;

n–;

}

return ele;

}

9、 返回元素的第n个兄弟节点

function retSibling(e, n) {

while (e && n) {

if (n > 0) {

if (e.nextElementSibling) {

e = e.nextElementSibling;

} else {

for (e = e.nextSibling; e && e.nodeType !== 1; e = e.nextSibling);

}

n–;

} else {

if (e.previousElementSibling) {

e = e.previousElementSibling;

} else {

for (e = e.previousElementSibling; e && e.nodeType !== 1; e = e.previousElementSibling);

}

n++;

}

}

return e;

}

10、封装mychildren，解决浏览器的兼容问题

function myChildren(e) {

var children = e.childNodes,

arr = [],

len = children.length;

for (var i = 0; i < len; i++) {

if (children[i].nodeType === 1) {

arr.push(children[i])

}

}

return arr;

}

11、判断元素有没有子元素

function hasChildren(e) {

var children = e.childNodes,

len = children.length;

for (var i = 0; i < len; i++) {

if (children[i].nodeType === 1) {

return true;

}

}

return false;

}

12、我一个元素插入到另一个元素的后面

Element.prototype.insertAfter = function (target, elen) {

var nextElen = elen.nextElenmentSibling;

if (nextElen == null) {

this.appendChild(target);

} else {

this.insertBefore(target, nextElen);

}

}

13、返回当前的时间（年月日时分秒）

function getDateTime() {

var date = new Date(),

year = date.getFullYear(),

month = date.getMonth() + 1,

day = date.getDate(),

hour = date.getHours() + 1,

minute = date.getMinutes(),

second = date.getSeconds();

month = checkTime(month);

day = checkTime(day);

hour = checkTime(hour);

minute = checkTime(minute);

second = checkTime(second);

function checkTime(i) {

if (i < 10) {

i = “0” + i;

}

return i;

}

return “” + year + “年” + month + “月” + day + “日” + hour + “时” + minute + “分” + second + “秒”

}

14、获得滚动条的滚动距离

function getScrollOffset() {

if (window.pageXOffset) {

return {

x: window.pageXOffset,

y: window.pageYOffset

}

} else {

return {

x: document.body.scrollLeft + document.documentElement.scrollLeft,

y: document.body.scrollTop + document.documentElement.scrollTop

}

}

}

15、获得视口的尺寸

function getViewportOffset() {

if (window.innerWidth) {

return {

w: window.innerWidth,

h: window.innerHeight

}

} else {

// ie8及其以下

if (document.compatMode === “BackCompat”) {

// 怪异模式

return {

w: document.body.clientWidth,

h: document.body.clientHeight

}

} else {

// 标准模式

return {

w: document.documentElement.clientWidth,

h: document.documentElement.clientHeight

}

}

}

}

16、获取任意元素的任意属性

function getStyle(elem, prop) {

return window.getComputedStyle ? window.getComputedStyle(elem, null)[prop] : elem.currentStyle[prop]

}

17、绑定事件的兼容代码

function addEvent(elem, type, handle) {

if (elem.addEventListener) { //非ie和非ie9

elem.addEventListener(type, handle, false);

} else if (elem.attachEvent) { //ie6到ie8

elem.attachEvent(‘on’ + type, function () {

handle.call(elem);

})

} else {

elem[‘on’ + type] = handle;

}

}

18、解绑事件

function removeEvent(elem, type, handle) {

if (elem.removeEventListener) { //非ie和非ie9

elem.removeEventListener(type, handle, false);

} else if (elem.detachEvent) { //ie6到ie8

elem.detachEvent(‘on’ + type, handle);

} else {

elem[‘on’ + type] = null;

}

}

19、取消冒泡的兼容代码

function stopBubble(e) {

if (e && e.stopPropagation) {

e.stopPropagation();

} else {

window.event.cancelBubble = true;

}

}

20、检验字符串是否是回文

function isPalina(str) {

if (Object.prototype.toString.call(str) !== ‘[object String]’) {

return false;

}

var len = str.length;

for (var i = 0; i < len / 2; i++) {

if (str[i] != str[len – 1 – i]) {

return false;

}

}

return true;

}

21、检验字符串是否是回文

function isPalindrome(str) {

str = str.replace(/W/g, ”).toLowerCase();

console.log(str)

return (str == str.split(”).reverse().join(”))

}

22、兼容getElementsByClassName方法

Element.prototype.getElementsByClassName = Document.prototype.getElementsByClassName = function (_className) {

var allDomArray = document.getElementsByTagName(‘*’);

var lastDomArray = [];

function trimSpace(strClass) {

var reg = /s+/g;

return strClass.replace(reg, ‘ ‘).trim()

}

for (var i = 0; i < allDomArray.length; i++) {

var classArray = trimSpace(allDomArray[i].className).split(‘ ‘);

for (var j = 0; j < classArray.length; j++) {

if (classArray[j] == _className) {

lastDomArray.push(allDomArray[i]);

break;

}

}

}

return lastDomArray;

}

23、运动函数

function animate(obj, json, callback) {

clearInterval(obj.timer);

var speed,

current;

obj.timer = setInterval(function () {

var lock = true;

for (var prop in json) {

if (prop == ‘opacity’) {

current = parseFloat(window.getComputedStyle(obj, null)[prop]) * 100;

} else {

current = parseInt(window.getComputedStyle(obj, null)[prop]);

}

speed = (json[prop] – current) / 7;

speed = speed > 0 ? Math.ceil(speed) : Math.floor(speed);

if (prop == ‘opacity’) {

obj.style[prop] = (current + speed) / 100;

} else {

obj.style[prop] = current + speed + ‘px’;

}

if (current != json[prop]) {

lock = false;

}

}

if (lock) {

clearInterval(obj.timer);

typeof callback == ‘function’ ? callback() : ”;

}

}, 30)

}

24、弹性运动

function ElasticMovement(obj, target) {

clearInterval(obj.timer);

var iSpeed = 40,

a, u = 0.8;

obj.timer = setInterval(function () {

a = (target – obj.offsetLeft) / 8;

iSpeed = iSpeed + a;

iSpeed = iSpeed * u;

if (Math.abs(iSpeed) <= 1 && Math.abs(a) <= 1) {

console.log(‘over’)

clearInterval(obj.timer);

obj.style.left = target + ‘px’;

} else {

obj.style.left = obj.offsetLeft + iSpeed + ‘px’;

}

}, 30);

}

25、封装自己的forEach方法

Array.prototype.myForEach = function (func, obj) {

var len = this.length;

var _this = arguments[1] ? arguments[1] : window;

// var _this=arguments[1]||window;

for (var i = 0; i < len; i++) {

func.call(_this, this[i], i, this)

}

}

26、封装自己的filter方法

Array.prototype.myFilter = function (func, obj) {

var len = this.length;

var arr = [];

var _this = arguments[1] || window;

for (var i = 0; i < len; i++) {

func.call(_this, this[i], i, this) && arr.push(this[i]);

}

return arr;

}

27、数组map方法

Array.prototype.myMap = function (func) {

var arr = [];

var len = this.length;

var _this = arguments[1] || window;

for (var i = 0; i < len; i++) {

arr.push(func.call(_this, this[i], i, this));

}

return arr;

}

28、数组every方法

Array.prototype.myEvery = function (func) {

var flag = true;

var len = this.length;

var _this = arguments[1] || window;

for (var i = 0; i < len; i++) {

if (func.apply(_this, [this[i], i, this]) == false) {

flag = false;

break;

}

}

return flag;

}

29、数组reduce方法

Array.prototype.myReduce = function (func, initialValue) {

var len = this.length,

nextValue,

i;

if (!initialValue) {

// 没有传第二个参数

nextValue = this[0];

i = 1;

} else {

// 传了第二个参数

nextValue = initialValue;

i = 0;

}

for (; i < len; i++) {

nextValue = func(nextValue, this[i], i, this);

}

return nextValue;

}

30、获取url中的参数

function getWindonHref() {

var sHref = window.location.href;

var args = sHref.split(‘?’);

if (args[0] === sHref) {

return ”;

}

var hrefarr = args[1].split(‘#’)[0].split(‘&’);

var obj = {};

for (var i = 0; i < hrefarr.length; i++) {

hrefarr[i] = hrefarr[i].split(‘=’);

obj[hrefarr[i][0]] = hrefarr[i][1];

}

return obj;

}

31、数组排序

// 快排 [left] + min + [right]

function quickArr(arr) {

if (arr.length <= 1) {

return arr;

}

var left = [],

right = [];

var pIndex = Math.floor(arr.length / 2);

var p = arr.splice(pIndex, 1)[0];

for (var i = 0; i < arr.length; i++) {

if (arr[i] <= p) {

left.push(arr[i]);

} else {

right.push(arr[i]);

}

}

// 递归

return quickArr(left).concat([p], quickArr(right));

}

// 冒泡

function bubbleSort(arr) {

for (var i = 0; i < arr.length – 1; i++) {

for (var j = i + 1; j < arr.length; j++) {

if (arr[i] > arr[j]) {

var temp = arr[i];

arr[i] = arr[j];

arr[j] = temp;

}

}

}

return arr;

}

function bubbleSort(arr) {

var len = arr.length;

for (var i = 0; i < len – 1; i++) {

for (var j = 0; j < len – 1 – i; j++) {

if (arr[j] > arr[j + 1]) {

var temp = arr[j];

arr[j] = arr[j + 1];

arr[j + 1] = temp;

}

}

}

return arr;

}

32、遍历Dom树

// 给定页面上的DOM元素,将访问元素本身及其所有后代(不仅仅是它的直接子元素)

// 对于每个访问的元素，函数将元素传递给提供的回调函数

function traverse(element, callback) {

callback(element);

var list = element.children;

for (var i = 0; i < list.length; i++) {

traverse(list[i], callback);

}

}

33、原生js封装ajax

function ajax(method, url, callback, data, flag) {

var xhr;

flag = flag || true;

method = method.toUpperCase();

if (window.XMLHttpRequest) {

xhr = new XMLHttpRequest();

} else {

xhr = new ActiveXObject(‘Microsoft.XMLHttp’);

}

xhr.onreadystatechange = function () {

if (xhr.readyState == 4 && xhr.status == 200) {

console.log(2)

callback(xhr.responseText);

}

}

if (method == ‘GET’) {

var date = new Date(),

timer = date.getTime();

xhr.open(‘GET’, url + ‘?’ + data + ‘&timer’ + timer, flag);

xhr.send()

} else if (method == ‘POST’) {

xhr.open(‘POST’, url, flag);

xhr.setRequestHeader(‘Content-Type’, ‘application/x-www-form-urlencoded’);

xhr.send(data);

}

}

34、异步加载script

function loadScript(url, callback) {

var oscript = document.createElement(‘script’);

if (oscript.readyState) { // ie8及以下版本

oscript.onreadystatechange = function () {

if (oscript.readyState === ‘complete’ || oscript.readyState === ‘loaded’) {

callback();

}

}

} else {

oscript.onload = function () {

callback()

};

}

oscript.src = url;

document.body.appendChild(oscript);

}

35、cookie管理

var cookie = {

set: function (name, value, time) {

document.cookie = name + ‘=’ + value + ‘; max-age=’ + time;

return this;

},

remove: function (name) {

return this.setCookie(name, ”, -1);

},

get: function (name, callback) {

var allCookieArr = document.cookie.split(‘; ‘);

for (var i = 0; i < allCookieArr.length; i++) {

var itemCookieArr = allCookieArr[i].split(‘=’);

if (itemCookieArr[0] === name) {

return itemCookieArr[1]

}

}

return undefined;

}

}

36、实现bind()方法

Function.prototype.myBind = function (target) {

var target = target || window;

var _args1 = [].slice.call(arguments, 1);

var self = this;

var temp = function () {};

var F = function () {

var _args2 = [].slice.call(arguments, 0);

var parasArr = _args1.concat(_args2);

return self.apply(this instanceof temp ? this : target, parasArr)

}

temp.prototype = self.prototype;

F.prototype = new temp();

return F;

}

37、实现call()方法

Function.prototype.myCall = function () {

var ctx = arguments[0] || window;

ctx.fn = this;

var args = [];

for (var i = 1; i < arguments.length; i++) {

args.push(arguments[i])

}

var result = ctx.fn(…args);

delete ctx.fn;

return result;

}

38、实现apply()方法

Function.prototype.myApply = function () {

var ctx = arguments[0] || window;

ctx.fn = this;

if (!arguments[1]) {

var result = ctx.fn();

delete ctx.fn;

return result;

}

var result = ctx.fn(…arguments[1]);

delete ctx.fn;

return result;

}

39、防抖

function debounce(handle, delay) {

var timer = null;

return function () {

var _self = this,

_args = arguments;

clearTimeout(timer);

timer = setTimeout(function () {

handle.apply(_self, _args)

}, delay)

}

}

40、节流

function throttle(handler, wait) {

var lastTime = 0;

return function (e) {

var nowTime = new Date().getTime();

if (nowTime – lastTime > wait) {

handler.apply(this, arguments);

lastTime = nowTime;

}

}

}

41、requestAnimFrame兼容性方法

window.requestAnimFrame = (function () {

return window.requestAnimationFrame ||

window.webkitRequestAnimationFrame ||

window.mozRequestAnimationFrame ||

function (callback) {

window.setTimeout(callback, 1000 / 60);

};

})();

42、cancelAnimFrame兼容性方法

window.cancelAnimFrame = (function () {

return window.cancelAnimationFrame ||

window.webkitCancelAnimationFrame ||

window.mozCancelAnimationFrame ||

function (id) {

window.clearTimeout(id);

};

})();

43、jsonp底层方法

function jsonp(url, callback) {

var oscript = document.createElement(‘script’);

if (oscript.readyState) { // ie8及以下版本

oscript.onreadystatechange = function () {

if (oscript.readyState === ‘complete’ || oscript.readyState === ‘loaded’) {

callback();

}

}

} else {

oscript.onload = function () {

callback()

};

}

oscript.src = url;

document.body.appendChild(oscript);

}

44、获取url上的参数

function getUrlParam(sUrl, sKey) {

var result = {};

sUrl.replace(/(w+)=(w+)(?=[&|#])/g, function (ele, key, val) {

if (!result[key]) {

result[key] = val;

} else {

var temp = result[key];

result[key] = [].concat(temp, val);

}

})

if (!sKey) {

return result;

} else {

return result[sKey] || ”;

}

}

45、格式化时间

function formatDate(t, str) {

var obj = {

yyyy: t.getFullYear(),

yy: (“” + t.getFullYear()).slice(-2),

M: t.getMonth() + 1,

MM: (“0” + (t.getMonth() + 1)).slice(-2),

d: t.getDate(),

dd: (“0” + t.getDate()).slice(-2),

H: t.getHours(),

HH: (“0” + t.getHours()).slice(-2),

h: t.getHours() % 12,

hh: (“0” + t.getHours() % 12).slice(-2),

m: t.getMinutes(),

mm: (“0” + t.getMinutes()).slice(-2),

s: t.getSeconds(),

ss: (“0” + t.getSeconds()).slice(-2),

w: [‘日’, ‘一’, ‘二’, ‘三’, ‘四’, ‘五’, ‘六’][t.getDay()]

};

return str.replace(/([a-z]+)/ig, function ($1) {

return obj[$1]

});

}

46、验证邮箱的正则表达式

function isAvailableEmail(sEmail) {

var reg = /^([w+.])+@w+([.]w+)+$/

return reg.test(sEmail)

}

47、函数颗粒化

//是把接受多个参数的函数变换成接受一个单一参数(最初函数的第一个参数)的函数，并且返回接受余下的参数且返回结果的新函数的技术

function curryIt(fn) {

var length = fn.length,

args = [];

var result = function (arg) {

args.push(arg);

length–;

if (length <= 0) {

return fn.apply(this, args);

} else {

return result;

}

}

return result;

}

48、大数相加

function sumBigNumber(a, b) {

var res = ”, //结果

temp = 0; //按位加的结果及进位

a = a.split(”);

b = b.split(”);

while (a.length || b.length || temp) {

//~~按位非 1.类型转换，转换成数字 2.~~undefined==0

temp += ~~a.pop() + ~~b.pop();

res = (temp % 10) + res;

temp = temp > 9;

}

return res.replace(/^0+/, ”);

}

1、输入一个值，返回其数据类型**

function type(para) {

return Object.prototype.toString.call(para)

}

2、数组去重

function unique1(arr) {

return […new Set(arr)]

}

function unique2(arr) {

var obj = {};

return arr.filter(ele => {

if (!obj[ele]) {

obj[ele] = true;

return true;

}

})

}

function unique3(arr) {

var result = [];

arr.forEach(ele => {

if (result.indexOf(ele) == -1) {

result.push(ele)

}

})

return result;

}

3、字符串去重

String.prototype.unique = function () {

var obj = {},

str = ”,

len = this.length;

for (var i = 0; i < len; i++) {

if (!obj[this[i]]) {

str += this[i];

obj[this[i]] = true;

}

}

return str;

}

###### //去除连续的字符串

function uniq(str) {

return str.replace(/(w)1+/g, ‘$1’)

}

4、深拷贝 浅拷贝

//深克隆（深克隆不考虑函数）

function deepClone(obj, result) {

var result = result || {};

for (var prop in obj) {

if (obj.hasOwnProperty(prop)) {

if (typeof obj[prop] == ‘object’ && obj[prop] !== null) {

// 引用值(obj/array)且不为null

if (Object.prototype.toString.call(obj[prop]) == ‘[object Object]’) {

// 对象

result[prop] = {};

} else {

// 数组

result[prop] = [];

}

deepClone(obj[prop], result[prop])

} else {

// 原始值或func

result[prop] = obj[prop]

}

}

}

return result;

}

// 深浅克隆是针对引用值

function deepClone(target) {

if (typeof (target) !== ‘object’) {

return target;

}

var result;

if (Object.prototype.toString.call(target) == ‘[object Array]’) {

// 数组

result = []

} else {

// 对象

result = {};

}

for (var prop in target) {

if (target.hasOwnProperty(prop)) {

result[prop] = deepClone(target[prop])

}

}

return result;

}

// 无法复制函数

var o1 = jsON.parse(jsON.stringify(obj1));

5、reverse底层原理和扩展

// 改变原数组

Array.prototype.myReverse = function () {

var len = this.length;

for (var i = 0; i < len; i++) {

var temp = this[i];

this[i] = this[len – 1 – i];

this[len – 1 – i] = temp;

}

return this;

}

6、圣杯模式的继承

function inherit(Target, Origin) {

function F() {};

F.prototype = Origin.prototype;

Target.prototype = new F();

Target.prototype.constructor = Target;

// 最终的原型指向

Target.prop.uber = Origin.prototype;

}

7、找出字符串中第一次只出现一次的字母

String.prototype.firstAppear = function () {

var obj = {},

len = this.length;

for (var i = 0; i < len; i++) {

if (obj[this[i]]) {

obj[this[i]]++;

} else {

obj[this[i]] = 1;

}

}

for (var prop in obj) {

if (obj[prop] == 1) {

return prop;

}

}

}

8、找元素的第n级父元素

function parents(ele, n) {

while (ele && n) {

ele = ele.parentElement ? ele.parentElement : ele.parentNode;

n–;

}

return ele;

}

9、 返回元素的第n个兄弟节点

function retSibling(e, n) {

while (e && n) {

if (n > 0) {

if (e.nextElementSibling) {

e = e.nextElementSibling;

} else {

for (e = e.nextSibling; e && e.nodeType !== 1; e = e.nextSibling);

}

n–;

} else {

if (e.previousElementSibling) {

e = e.previousElementSibling;

} else {

for (e = e.previousElementSibling; e && e.nodeType !== 1; e = e.previousElementSibling);

}

n++;

}

}

return e;

}

10、封装mychildren，解决浏览器的兼容问题

function myChildren(e) {

var children = e.childNodes,

arr = [],

len = children.length;

for (var i = 0; i < len; i++) {

if (children[i].nodeType === 1) {

arr.push(children[i])

}

}

return arr;

}

11、判断元素有没有子元素

function hasChildren(e) {

var children = e.childNodes,

len = children.length;

for (var i = 0; i < len; i++) {

if (children[i].nodeType === 1) {

return true;

}

}

return false;

}

12、我一个元素插入到另一个元素的后面

Element.prototype.insertAfter = function (target, elen) {

var nextElen = elen.nextElenmentSibling;

if (nextElen == null) {

this.appendChild(target);

} else {

this.insertBefore(target, nextElen);

}

}

13、返回当前的时间（年月日时分秒）

function getDateTime() {

var date = new Date(),

year = date.getFullYear(),

month = date.getMonth() + 1,

day = date.getDate(),

hour = date.getHours() + 1,

minute = date.getMinutes(),

second = date.getSeconds();

month = checkTime(month);

day = checkTime(day);

hour = checkTime(hour);

minute = checkTime(minute);

second = checkTime(second);

function checkTime(i) {

if (i < 10) {

i = “0” + i;

}

return i;

}

return “” + year + “年” + month + “月” + day + “日” + hour + “时” + minute + “分” + second + “秒”

}

14、获得滚动条的滚动距离

function getScrollOffset() {

if (window.pageXOffset) {

return {

x: window.pageXOffset,

y: window.pageYOffset

}

} else {

return {

x: document.body.scrollLeft + document.documentElement.scrollLeft,

y: document.body.scrollTop + document.documentElement.scrollTop

}

}

}

15、获得视口的尺寸

function getViewportOffset() {

if (window.innerWidth) {

return {

w: window.innerWidth,

h: window.innerHeight

}

} else {

// ie8及其以下

if (document.compatMode === “BackCompat”) {

// 怪异模式

return {

w: document.body.clientWidth,

h: document.body.clientHeight

}

} else {

// 标准模式

return {

w: document.documentElement.clientWidth,

h: document.documentElement.clientHeight

}

}

}

}

16、获取任意元素的任意属性

function getStyle(elem, prop) {

return window.getComputedStyle ? window.getComputedStyle(elem, null)[prop] : elem.currentStyle[prop]

}

17、绑定事件的兼容代码

function addEvent(elem, type, handle) {

if (elem.addEventListener) { //非ie和非ie9

elem.addEventListener(type, handle, false);

} else if (elem.attachEvent) { //ie6到ie8

elem.attachEvent(‘on’ + type, function () {

handle.call(elem);

})

} else {

elem[‘on’ + type] = handle;

}

}

18、解绑事件

function removeEvent(elem, type, handle) {

if (elem.removeEventListener) { //非ie和非ie9

elem.removeEventListener(type, handle, false);

} else if (elem.detachEvent) { //ie6到ie8

elem.detachEvent(‘on’ + type, handle);

} else {

elem[‘on’ + type] = null;

}

}

19、取消冒泡的兼容代码

function stopBubble(e) {

if (e && e.stopPropagation) {

e.stopPropagation();

} else {

window.event.cancelBubble = true;

}

}

20、检验字符串是否是回文

function isPalina(str) {

if (Object.prototype.toString.call(str) !== ‘[object String]’) {

return false;

}

var len = str.length;

for (var i = 0; i < len / 2; i++) {

if (str[i] != str[len – 1 – i]) {

return false;

}

}

return true;

}

21、检验字符串是否是回文

function isPalindrome(str) {

str = str.replace(/W/g, ”).toLowerCase();

console.log(str)

return (str == str.split(”).reverse().join(”))

}

22、兼容getElementsByClassName方法

Element.prototype.getElementsByClassName = Document.prototype.getElementsByClassName = function (_className) {

var allDomArray = document.getElementsByTagName(‘*’);

var lastDomArray = [];

function trimSpace(strClass) {

var reg = /s+/g;

return strClass.replace(reg, ‘ ‘).trim()

}

for (var i = 0; i < allDomArray.length; i++) {

var classArray = trimSpace(allDomArray[i].className).split(‘ ‘);

for (var j = 0; j < classArray.length; j++) {

if (classArray[j] == _className) {

lastDomArray.push(allDomArray[i]);

break;

}

}

}

return lastDomArray;

}

23、运动函数

function animate(obj, json, callback) {

clearInterval(obj.timer);

var speed,

current;

obj.timer = setInterval(function () {

var lock = true;

for (var prop in json) {

if (prop == ‘opacity’) {

current = parseFloat(window.getComputedStyle(obj, null)[prop]) * 100;

} else {

current = parseInt(window.getComputedStyle(obj, null)[prop]);

}

speed = (json[prop] – current) / 7;

speed = speed > 0 ? Math.ceil(speed) : Math.floor(speed);

if (prop == ‘opacity’) {

obj.style[prop] = (current + speed) / 100;

} else {

obj.style[prop] = current + speed + ‘px’;

}

if (current != json[prop]) {

lock = false;

}

}

if (lock) {

clearInterval(obj.timer);

typeof callback == ‘function’ ? callback() : ”;

}

}, 30)

}

24、弹性运动

function ElasticMovement(obj, target) {

clearInterval(obj.timer);

var iSpeed = 40,

a, u = 0.8;

obj.timer = setInterval(function () {

a = (target – obj.offsetLeft) / 8;

iSpeed = iSpeed + a;

iSpeed = iSpeed * u;

if (Math.abs(iSpeed) <= 1 && Math.abs(a) <= 1) {

console.log(‘over’)

clearInterval(obj.timer);

obj.style.left = target + ‘px’;

} else {

obj.style.left = obj.offsetLeft + iSpeed + ‘px’;

}

}, 30);

}

25、封装自己的forEach方法

Array.prototype.myForEach = function (func, obj) {

var len = this.length;

var _this = arguments[1] ? arguments[1] : window;

// var _this=arguments[1]||window;

for (var i = 0; i < len; i++) {

func.call(_this, this[i], i, this)

}

}

26、封装自己的filter方法

Array.prototype.myFilter = function (func, obj) {

var len = this.length;

var arr = [];

var _this = arguments[1] || window;

for (var i = 0; i < len; i++) {

func.call(_this, this[i], i, this) && arr.push(this[i]);

}

return arr;

}

27、数组map方法

Array.prototype.myMap = function (func) {

var arr = [];

var len = this.length;

var _this = arguments[1] || window;

for (var i = 0; i < len; i++) {

arr.push(func.call(_this, this[i], i, this));

}

return arr;

}

28、数组every方法

Array.prototype.myEvery = function (func) {

var flag = true;

var len = this.length;

var _this = arguments[1] || window;

for (var i = 0; i < len; i++) {

if (func.apply(_this, [this[i], i, this]) == false) {

flag = false;

break;

}

}

return flag;

}

29、数组reduce方法

Array.prototype.myReduce = function (func, initialValue) {

var len = this.length,

nextValue,

i;

if (!initialValue) {

// 没有传第二个参数

nextValue = this[0];

i = 1;

} else {

// 传了第二个参数

nextValue = initialValue;

i = 0;

}

for (; i < len; i++) {

nextValue = func(nextValue, this[i], i, this);

}

return nextValue;

}

30、获取url中的参数

function getWindonHref() {

var sHref = window.location.href;

var args = sHref.split(‘?’);

if (args[0] === sHref) {

return ”;

}

var hrefarr = args[1].split(‘#’)[0].split(‘&’);

var obj = {};

for (var i = 0; i < hrefarr.length; i++) {

hrefarr[i] = hrefarr[i].split(‘=’);

obj[hrefarr[i][0]] = hrefarr[i][1];

}

return obj;

}

31、数组排序

// 快排 [left] + min + [right]

function quickArr(arr) {

if (arr.length <= 1) {

return arr;

}

var left = [],

right = [];

var pIndex = Math.floor(arr.length / 2);

var p = arr.splice(pIndex, 1)[0];

for (var i = 0; i < arr.length; i++) {

if (arr[i] <= p) {

left.push(arr[i]);

} else {

right.push(arr[i]);

}

}

// 递归

return quickArr(left).concat([p], quickArr(right));

}

// 冒泡

function bubbleSort(arr) {

for (var i = 0; i < arr.length – 1; i++) {

for (var j = i + 1; j < arr.length; j++) {

if (arr[i] > arr[j]) {

var temp = arr[i];

arr[i] = arr[j];

arr[j] = temp;

}

}

}

return arr;

}

function bubbleSort(arr) {

var len = arr.length;

for (var i = 0; i < len – 1; i++) {

for (var j = 0; j < len – 1 – i; j++) {

if (arr[j] > arr[j + 1]) {

var temp = arr[j];

arr[j] = arr[j + 1];

arr[j + 1] = temp;

}

}

}

return arr;

}

32、遍历Dom树

// 给定页面上的DOM元素,将访问元素本身及其所有后代(不仅仅是它的直接子元素)

// 对于每个访问的元素，函数将元素传递给提供的回调函数

function traverse(element, callback) {

callback(element);

var list = element.children;

for (var i = 0; i < list.length; i++) {

traverse(list[i], callback);

}

}

33、原生js封装ajax

function ajax(method, url, callback, data, flag) {

var xhr;

flag = flag || true;

method = method.toUpperCase();

if (window.XMLHttpRequest) {

xhr = new XMLHttpRequest();

} else {

xhr = new ActiveXObject(‘Microsoft.XMLHttp’);

}

xhr.onreadystatechange = function () {

if (xhr.readyState == 4 && xhr.status == 200) {

console.log(2)

callback(xhr.responseText);

}

}

if (method == ‘GET’) {

var date = new Date(),

timer = date.getTime();

xhr.open(‘GET’, url + ‘?’ + data + ‘&timer’ + timer, flag);

xhr.send()

} else if (method == ‘POST’) {

xhr.open(‘POST’, url, flag);

xhr.setRequestHeader(‘Content-Type’, ‘application/x-www-form-urlencoded’);

xhr.send(data);

}

}

34、异步加载script

function loadScript(url, callback) {

var oscript = document.createElement(‘script’);

if (oscript.readyState) { // ie8及以下版本

oscript.onreadystatechange = function () {

if (oscript.readyState === ‘complete’ || oscript.readyState === ‘loaded’) {

callback();

}

}

} else {

oscript.onload = function () {

callback()

};

}

oscript.src = url;

document.body.appendChild(oscript);

}

35、cookie管理

var cookie = {

set: function (name, value, time) {

document.cookie = name + ‘=’ + value + ‘; max-age=’ + time;

return this;

},

remove: function (name) {

return this.setCookie(name, ”, -1);

},

get: function (name, callback) {

var allCookieArr = document.cookie.split(‘; ‘);

for (var i = 0; i < allCookieArr.length; i++) {

var itemCookieArr = allCookieArr[i].split(‘=’);

if (itemCookieArr[0] === name) {

return itemCookieArr[1]

}

}

return undefined;

}

}

36、实现bind()方法

Function.prototype.myBind = function (target) {

var target = target || window;

var _args1 = [].slice.call(arguments, 1);

var self = this;

var temp = function () {};

var F = function () {

var _args2 = [].slice.call(arguments, 0);

var parasArr = _args1.concat(_args2);

return self.apply(this instanceof temp ? this : target, parasArr)

}

temp.prototype = self.prototype;

F.prototype = new temp();

return F;

}

37、实现call()方法

Function.prototype.myCall = function () {

var ctx = arguments[0] || window;

ctx.fn = this;

var args = [];

for (var i = 1; i < arguments.length; i++) {

args.push(arguments[i])

}

var result = ctx.fn(…args);

delete ctx.fn;

return result;

}

38、实现apply()方法

Function.prototype.myApply = function () {

var ctx = arguments[0] || window;

ctx.fn = this;

if (!arguments[1]) {

var result = ctx.fn();

delete ctx.fn;

return result;

}

var result = ctx.fn(…arguments[1]);

delete ctx.fn;

return result;

}

39、防抖

function debounce(handle, delay) {

var timer = null;

return function () {

var _self = this,

_args = arguments;

clearTimeout(timer);

timer = setTimeout(function () {

handle.apply(_self, _args)

}, delay)

}

}

40、节流

function throttle(handler, wait) {

var lastTime = 0;

return function (e) {

var nowTime = new Date().getTime();

if (nowTime – lastTime > wait) {

handler.apply(this, arguments);

lastTime = nowTime;

}

}

}

41、requestAnimFrame兼容性方法

window.requestAnimFrame = (function () {

return window.requestAnimationFrame ||

window.webkitRequestAnimationFrame ||

window.mozRequestAnimationFrame ||

function (callback) {

window.setTimeout(callback, 1000 / 60);

};

})();

42、cancelAnimFrame兼容性方法

window.cancelAnimFrame = (function () {

return window.cancelAnimationFrame ||

window.webkitCancelAnimationFrame ||

window.mozCancelAnimationFrame ||

function (id) {

window.clearTimeout(id);

};

})();

43、jsonp底层方法

function jsonp(url, callback) {

var oscript = document.createElement(‘script’);

if (oscript.readyState) { // ie8及以下版本

oscript.onreadystatechange = function () {

if (oscript.readyState === ‘complete’ || oscript.readyState === ‘loaded’) {

callback();

}

}

} else {

oscript.onload = function () {

callback()

};

}

oscript.src = url;

document.body.appendChild(oscript);

}

44、获取url上的参数

function getUrlParam(sUrl, sKey) {

var result = {};

sUrl.replace(/(w+)=(w+)(?=[&|#])/g, function (ele, key, val) {

if (!result[key]) {

result[key] = val;

} else {

var temp = result[key];

result[key] = [].concat(temp, val);

}

})

if (!sKey) {

return result;

} else {

return result[sKey] || ”;

}

}

45、格式化时间

function formatDate(t, str) {

var obj = {

yyyy: t.getFullYear(),

yy: (“” + t.getFullYear()).slice(-2),

M: t.getMonth() + 1,

MM: (“0” + (t.getMonth() + 1)).slice(-2),

d: t.getDate(),

dd: (“0” + t.getDate()).slice(-2),

H: t.getHours(),

HH: (“0” + t.getHours()).slice(-2),

h: t.getHours() % 12,

hh: (“0” + t.getHours() % 12).slice(-2),

m: t.getMinutes(),

mm: (“0” + t.getMinutes()).slice(-2),

s: t.getSeconds(),

ss: (“0” + t.getSeconds()).slice(-2),

w: [‘日’, ‘一’, ‘二’, ‘三’, ‘四’, ‘五’, ‘六’][t.getDay()]

};

return str.replace(/([a-z]+)/ig, function ($1) {

return obj[$1]

});

}

46、验证邮箱的正则表达式

function isAvailableEmail(sEmail) {

var reg = /^([w+.])+@w+([.]w+)+$/

return reg.test(sEmail)

}

47、函数颗粒化

//是把接受多个参数的函数变换成接受一个单一参数(最初函数的第一个参数)的函数，并且返回接受余下的参数且返回结果的新函数的技术

function curryIt(fn) {

var length = fn.length,

args = [];

var result = function (arg) {

args.push(arg);

length–;

if (length <= 0) {

return fn.apply(this, args);

} else {

return result;

}

}

return result;

}

48、大数相加

function sumBigNumber(a, b) {

var res = ”, //结果

temp = 0; //按位加的结果及进位

a = a.split(”);

b = b.split(”);

while (a.length || b.length || temp) {

//~~按位非 1.类型转换，转换成数字 2.~~undefined==0

temp += ~~a.pop() + ~~b.pop();

res = (temp % 10) + res;

temp = temp > 9;

}

return res.replace(/^0+/, ”);

}

49、单例模式

function getSingle(func) {

var result;

return function () {

if (!result) {

result = new func(arguments);

}

return result;

}

}

49、单例模式

function getSingle(func) {

var result;

return function () {

if (!result) {

result = new func(arguments);

}

return result;

}

}