常用的前端JavaScript方法封装

获取url中的参

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;
}

//方法二
const getUrlParam = function(name) { // 获取url参数
  let reg = new RegExp('(^|&?)' + name + '=([^&]*)(&|$)', 'i')
  let r = window.location.href.substr(1).match(reg)
  if (r != null) {
    return decodeURI(r[2])
  }
  return undefined
}
//方法三
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] || '';
    }
}

输入一个值，返回其数据类型

function type(para) {
    return Object.prototype.toString.call(para)
}

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"
}

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;
}

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')
}

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;
}

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;
}

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;
       }
    }
}

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;
}

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;
}

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;
}

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);
    }
}

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
        }
    }
}

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
            }
        }
    }
}

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]
}

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;
    }
}

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;
    }
}

取消冒泡的兼容代码

function stopBubble(e) {
    if (e && e.stopPropagation) {
        e.stopPropagation();
    } else {
        window.event.cancelBubble = true;
    }
}

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;
}

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;
}

遍历Dom树

function traverse(element, callback) {
    callback(element);
    var list = element.children;
    for (var i = 0; i < list.length; i++) {
        traverse(list[i], callback);
    }
}

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);
    }
}

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;
    }
}

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)
    }
}

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;
        }
    }
}

常用正则验证

const checkStr = function(str, type) { // 常用正则验证，注意type大小写
  switch (type) {
    case 'phone': // 手机号码
      return /^1[3|4|5|6|7|8|9][0-9]{9}$/.test(str)
    case 'tel': // 座机
      return /^(0\d{2,3}-\d{7,8})(-\d{1,4})?$/.test(str)
    case 'card': // 身份证
      return /(^\d{15}$)|(^\d{18}$)|(^\d{17}(\d|X|x)$)/.test(str)
    case 'pwd': // 密码以字母开头，长度在6~18之间，只能包含字母、数字和下划线
      return /^[a-zA-Z]\w{5,17}$/.test(str)
    case 'postal': // 邮政编码
      return /[1-9]\d{5}(?!\d)/.test(str)
    case 'QQ': // QQ号
      return /^[1-9][0-9]{4,9}$/.test(str)
    case 'email': // 邮箱
      return /^[\w-]+(\.[\w-]+)*@[\w-]+(\.[\w-]+)+$/.test(str)
    case 'money': // 金额(小数点2位)
      return /^\d*(?:\.\d{0,2})?$/.test(str)
    case 'URL': // 网址
      return /(http|ftp|https):\/\/[\w\-_]+(\.[\w\-_]+)+([\w\-\.,@?^=%&:/~\+#]*[\w\-\@?^=%&/~\+#])?/.test(str)
    case 'IP': // IP
      return /((?:(?:25[0-5]|2[0-4]\\d|[01]?\\d?\\d)\\.){3}(?:25[0-5]|2[0-4]\\d|[01]?\\d?\\d))/.test(str)
    case 'date': // 日期时间
      return /^(\d{4})\-(\d{2})\-(\d{2}) (\d{2})(?:\:\d{2}|:(\d{2}):(\d{2}))$/.test(str) ||
        /^(\d{4})\-(\d{2})\-(\d{2})$/.test(str)
    case 'number': // 数字
      return /^[0-9]$/.test(str)
    case 'english': // 英文
      return /^[a-zA-Z]+$/.test(str)
    case 'chinese': // 中文
      return /^[\u4E00-\u9FA5]+$/.test(str)
    case 'lower': // 小写
      return /^[a-z]+$/.test(str)
    case 'upper': // 大写
      return /^[A-Z]+$/.test(str)
    case 'HTML': // HTML标记
      return /<("[^"]*"|'[^']*'|[^'">])*>/.test(str)
    default:
      return true
  }
}

图片地址转base64

const getBase64 = function(img) { //传入图片路径，返回base64，使用getBase64(url).then(function(base64){},function(err){}); 
  let getBase64Image = function(img, width, height) { //width、height调用时传入具体像素值，控制大小,不传则默认图像大小
    let canvas = document.createElement("canvas");
    canvas.width = width ? width : img.width;
    canvas.height = height ? height : img.height;
    let ctx = canvas.getContext("2d");
    ctx.drawImage(img, 0, 0, canvas.width, canvas.height);
    let dataURL = canvas.toDataURL();
    return dataURL;
  }
  let image = new Image();
  image.crossOrigin = '';
  image.src = img;
  let deferred = $.Deferred();
  if (img) {
    image.onload = function() {
      deferred.resolve(getBase64Image(image));
    }
    return deferred.promise();
  }
}

base64图片下载功能

const downloadFile = function(base64, fileName) { //base64图片下载功能
  let base64ToBlob = function(code) {
    let parts = code.split(';base64,');
    let contentType = parts[0].split(':')[1];
    let raw = window.atob(parts[1]);
    let rawLength = raw.length;
    let uInt8Array = new Uint8Array(rawLength);
    for (let i = 0; i < rawLength; ++i) {
      uInt8Array[i] = raw.charCodeAt(i);
    }
    return new Blob([uInt8Array], {
      type: contentType
    });
  };
  let aLink = document.createElement('a');
  let blob = base64ToBlob(base64); //new Blob([content]);
  let evt = document.createEvent("HTMLEvents");
  evt.initEvent("click", true, true); //initEvent不加后两个参数在FF下会报错  事件类型，是否冒泡，是否阻止浏览器的默认行为
  aLink.download = fileName;
  aLink.href = URL.createObjectURL(blob);
  aLink.click();
}