常用的JavaScript方法封装

1、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
        }
    }
}

2、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
            }
        }
    }
}

3、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)
    }
}

4、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;
}

5、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;
}

6、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;
}

7、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;
}

8、设备判断：android、ios、web

const isDevice = function() { // 判断是android还是ios还是web
  var ua = navigator.userAgent.toLowerCase()
  if (ua.match(/iPhone\sOS/i) === 'iphone os' || ua.match(/iPad/i) === 'ipad') { // ios
    return 'iOS'
  }
  if (ua.match(/Android/i) === 'android') {
    return 'Android'
  }
  return 'Web'
}

9、文本复制功能

const copyTxt = function(text, fn) { // 复制功能
  if (typeof document.execCommand !== 'function') {
    console.log('复制失败，请长按复制')
    return
  }
  var dom = document.createElement('textarea')
  dom.value = text
  dom.setAttribute('style', 'display: block;width: 1px;height: 1px;')
  document.body.appendChild(dom)
  dom.select()
  var result = document.execCommand('copy')
  document.body.removeChild(dom)
  if (result) {
    console.log('复制成功')
    typeof fn === 'function' && fn()
    return
  }
  if (typeof document.createRange !== 'function') {
    console.log('复制失败，请长按复制')
    return
  }
  var range = document.createRange()
  var div = document.createElement('div')
  div.innerhtml = text
  div.setAttribute('style', 'height: 1px;fontSize: 1px;overflow: hidden;')
  document.body.appendChild(div)
  range.selectNode(div)
  var selection = window.getSelection()
  console.log(selection)
  if (selection.rangeCount > 0) {
    selection.removeAllRanges()
  }
  selection.addRange(range)
  document.execCommand('copy')
  typeof fn === 'function' && fn()
  console.log('复制成功')
}

10 根据url地址下载

export const download = (url)=>{
var isChrome = navigator.userAgent.toLowerCase().indexOf('chrome')>-1;
var isSafari = navigator.userAgent.toLowerCase().indexOf('safari')>-1;
if(isChrome || isSafari){
var link = document.createElement('a');
link.href = url;
if(link.download !== undefined){
var fileName = url.substring(url.lastIndexOf('/')+1,url.length);
link.download = fileName
}
if(document.createEvent){
var e = document.createEvent('MouseEvents');
e.initEvent('click',true,true);
link.dispatchEvent(e);
return true;
}
}
if(url.indexOf('?')===-1){
url+='?download'
}
window.open(url,'_self');
return true;
}

11、el添加某个class

export const addClass = (el,className)=>{
if(hasClass(el,className)){
return
}
let newClass = el.className.split(' ')
newClass.push(className)
el.className = newClass.join(' ')
}

11 、el去除某个class

export cosnt removeClass = (el,className)=>{
if(!hasClass(el,className)){
return
}
let reg = new RegExp('(^|\\s)'+className+'(\\s|$)','g')
el.className = el.className.replace(reg,'')
}

12 、将类数组转换为数组

export const formArray = (ary) => { 
var arr = [];
if (Array.isArray(ary)) {
arr = ary;
} else {
arr = Array.prototype.slice.call(ary); 
}; 
return arr; 
}

13、去除空格,type: 1-所有空格 2-前后空格 3-前空格 4-后空格

export const trim = (str, type) => {
type = type || 1 
switch (type) { 
case 1: 
return str.replace(/\s+/g, "");
case 2:
return str.replace(/(^\s*)|(\s*$)/g, "");
case 3:
return str.replace(/(^\s*)/g, "");
case 4: 
return str.replace(/(\s*$)/g, ""); 
default: 
return str;
} 
}

14、 判断两个对象是否键值相同

export const isObjectEqual = (a, b) => { 
var aProps = Object.getOwnPropertyNames(a);
var bProps = Object.getOwnPropertyNames(b); 
if (aProps.length !== bProps.length) {
return false; 
} 
for (var i = 0; i < aProps.length; i++) {
var propName = aProps[i]; 
if (a[propName] !== b[propName]) {
return false; 
} 
}
return true;
}