49个常用的前端JavaScript方法封装

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;}
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，函数讲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
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;    }## }