常用的前端JavaScript方法封装（49种）

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;
}
})
}

//去除连续的字符串

// 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、获取任一元素的任意属性
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;
}

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[ $KaTeX parse error: Expected 'EOF', got '}' at position 8: 1] }̲); } 46、验证邮箱的正则\dots$ /
return reg.test(sEmail)
}
47、函数柯里化
//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