JS常用工具函数

1.isArray:判断数据是不是数组类型的数据

function isArray(arr) {
    return Object.prototype.toString.call(arr) === '[object Array]'
}

Array.isArray = Array.isArray || isArray // 将isArray挂载到Array上

2.isFunction:检查 value 是不是函数

function isFunction(value) {
    return Object.prototype.toString.call(value) === '[object Function]'
}

3.capitalize:字符串首位大写

function capitalize(str){
    return str.charAt(0).toUpperCase() + str.slice(1)
}

4.extend:将属性混合到目标对象中

function extend(to, _from) {
    for(let key in _from) {
        to[key] = _from[key];
    }
    return to
}

5.识别各种浏览器及平台

// 运行环境是浏览器
let inBrowser = typeof window !== 'undefined';
// 运行环境是微信
let inWeex = typeof WXEnvironment !== 'undefined' && !!WXEnvironment.platform;
let weexPlatform = inWeex && WXEnvironment.platform.toLowerCase();
// 浏览器 UA 判断
let UA = inBrowser && window.navigator.userAgent.toLowerCase();
let isIE = UA && /msie|trident/.test(UA);
let isIE9 = UA && UA.indexOf('msie 9.0') > 0;
let isEdge = UA && UA.indexOf('edge/') > 0;
let isAndroid = (UA && UA.indexOf('android') > 0) || (weexPlatform === 'android');
let isIOS = (UA && /iphone|ipad|ipod|ios/.test(UA)) || (weexPlatform === 'ios');
let isChrome = UA && /chrome\/\d+/.test(UA) && !isEdge;

6.getExplorerInfo:获取浏览器信息

function getExplorerInfo() {
    let t = navigator.userAgent.toLowerCase();
    return 0 <= t.indexOf("msie") ? { //ie < 11
        type: "IE",
        version: Number(t.match(/msie ([\d]+)/)[1])
    } : !!t.match(/trident\/.+?rv:(([\d.]+))/) ? { // ie 11
        type: "IE",
        version: 11
    } : 0 <= t.indexOf("edge") ? {
        type: "Edge",
        version: Number(t.match(/edge\/([\d]+)/)[1])
    } : 0 <= t.indexOf("firefox") ? {
        type: "Firefox",
        version: Number(t.match(/firefox\/([\d]+)/)[1])
    } : 0 <= t.indexOf("chrome") ? {
        type: "Chrome",
        version: Number(t.match(/chrome\/([\d]+)/)[1])
    } : 0 <= t.indexOf("opera") ? {
        type: "Opera",
        version: Number(t.match(/opera.([\d]+)/)[1])
    } : 0 <= t.indexOf("Safari") ? {
        type: "Safari",
        version: Number(t.match(/version\/([\d]+)/)[1])
    } : {
        type: t,
        version: -1
    }
}

7.isPCBroswer:检测是否为PC端浏览器模式

function isPCBroswer() {
    let e = navigator.userAgent.toLowerCase()
        , t = "ipad" == e.match(/ipad/i)
        , i = "iphone" == e.match(/iphone/i)
        , r = "midp" == e.match(/midp/i)
        , n = "rv:1.2.3.4" == e.match(/rv:1.2.3.4/i)
        , a = "ucweb" == e.match(/ucweb/i)
        , o = "android" == e.match(/android/i)
        , s = "windows ce" == e.match(/windows ce/i)
        , l = "windows mobile" == e.match(/windows mobile/i);
    return !(t || i || r || n || a || o || s || l)
}

8.dateFormater:格式化时间

function dateFormater(formater, t){
    let date = t ? new Date(t) : new Date(),
        Y = date.getFullYear() + '',
        M = date.getMonth() + 1,
        D = date.getDate(),
        H = date.getHours(),
        m = date.getMinutes(),
        s = date.getSeconds();
    return formater.replace(/YYYY|yyyy/g,Y)
        .replace(/YY|yy/g,Y.substr(2,2))
        .replace(/MM/g,(M<10?'0':'') + M)
        .replace(/DD/g,(D<10?'0':'') + D)
        .replace(/HH|hh/g,(H<10?'0':'') + H)
        .replace(/mm/g,(m<10?'0':'') + m)
        .replace(/ss/g,(s<10?'0':'') + s)
}
// dateFormater('YYYY-MM-DD HH:mm', t) ==> 2019-06-26 18:30
// dateFormater('YYYYMMDDHHmm', t) ==> 201906261830

9.dateStrForma:将指定字符串由一种时间格式转化为另一种

function dateStrForma(str, from, to){
    //'20190626' 'YYYYMMDD' 'YYYY年MM月DD日'
    str += ''
    let Y = ''
    if(~(Y = from.indexOf('YYYY'))){
        Y = str.substr(Y, 4)
        to = to.replace(/YYYY|yyyy/g,Y)
    }else if(~(Y = from.indexOf('YY'))){
        Y = str.substr(Y, 2)
        to = to.replace(/YY|yy/g,Y)
    }

    let k,i
    ['M','D','H','h','m','s'].forEach(s =>{
        i = from.indexOf(s+s)
        k = ~i ? str.substr(i, 2) : ''
        to = to.replace(s+s, k)
    })
    return to
}
// dateStrForma('20190626', 'YYYYMMDD', 'YYYY年MM月DD日') ==> 2019年06月26日
// dateStrForma('121220190626', '----YYYYMMDD', 'YYYY年MM月DD日') ==> 2019年06月26日
// dateStrForma('2019年06月26日', 'YYYY年MM月DD日', 'YYYYMMDD') ==> 20190626    
// 一般的也可以使用正则来实现
// '2019年06月26日'.replace(/(\d{4})年(\d{2})月(\d{2})日/, '$1-$2-$3') ==> 2019-06-26

10.GetUrlParam:获取Url参数,返回一个对象

function GetUrlParam(){
    let url = document.location.toString();
    let arrObj = url.split("?");
    let params = Object.create(null)
    if (arrObj.length > 1){
        arrObj = arrObj[1].split("&");
        arrObj.forEach(item=>{
            item = item.split("=");
            params[item[0]] = item[1]
        })
    }
    return params;
}
// ?a=1&b=2&c=3 ==> {a: "1", b: "2", c: "3"}

11.toFullScreen:全屏

function toFullScreen(){
    let elem = document.body;
    elem.webkitRequestFullScreen 
    ? elem.webkitRequestFullScreen()
    : elem.mozRequestFullScreen
    ? elem.mozRequestFullScreen()
    : elem.msRequestFullscreen
    ? elem.msRequestFullscreen()
    : elem.requestFullScreen
    ? elem.requestFullScreen()
    : alert("浏览器不支持全屏");
}

12.exitFullscreen:退出全屏

function exitFullscreen(){
    let elem = parent.document;
    elem.webkitCancelFullScreen 
    ? elem.webkitCancelFullScreen()
    : elem.mozCancelFullScreen
    ? elem.mozCancelFullScreen()
    : elem.cancelFullScreen
    ? elem.cancelFullScreen()
    : elem.msExitFullscreen
    ? elem.msExitFullscreen()
    : elem.exitFullscreen
    ? elem.exitFullscreen()
    : alert("切换失败,可尝试Esc退出");
}

13._isNaN:检查数据是否是非数字值

function _isNaN(v){
    return !(typeof v === 'string' || typeof v === 'number') || isNaN(v)
}

14.max:求取数组中非NaN数据中的最大值

function max(arr){
    arr = arr.filter(item => !_isNaN(item))
    return arr.length ? Math.max.apply(null, arr) : undefined
}
// max([1, 2, '11', null, 'fdf', []]) ==> 11

15.min:求取数组中非NaN数据中的最小值

function min(arr){
    arr = arr.filter(item => !_isNaN(item))
    return arr.length ? Math.min.apply(null, arr) : undefined
}
// min([1, 2, '11', null, 'fdf', []]) ==> 1

16.random:返回一个lower-upper之间的随机数,包含lower

function random(lower, upper){
    lower = +lower || 0
    upper = +upper || 0
    return Math.random() * (upper - lower) + lower // 不包含upper
    return Math.random() * (upper - lower + 1) + lower // 包含upper
    return Math.floor(Math.random() * (upper - lower)) + lower // 整数
    return Math.floor(Math.random() * (upper - lower + 1)) + lower // 整数
}
// random(0, 0.5) ==> 0.3567039135734613
// random(2, 1) ===> 1.6718418553475423
// random(-2, -1) ==> -1.4474325452361945