好久没写简书,今天看大神的代码里面,好多封装好的工具函数,忍不住想偷师一下,所以在这里总结一下

1. 大数值转换和保留n位有效数字

 function numberFormatter(num, digits) {
            const si = [
                { value: 1E13, symbol: '亿亿' },
                { value: 1E12, symbol: '万亿' },
                { value: 1E11, symbol: '千亿' },
                { value: 1E10, symbol: '百亿' },
                { value: 1E9, symbol: '十亿' },
                { value: 1E8, symbol: '亿' },
                { value: 1E7, symbol: '千万' },
                { value: 1E6, symbol: '百万' },
                { value: 1E5, symbol: '十万' },
                { value: 1E4, symbol: '万' },
                { value: 1E3, symbol: '千' }
            ]
            for (let i = 0; i < si.length; i++) {
                if (num >= si[i].value) {
                    return (num / si[i].value).toFixed(digits).replace(/\.0+$|(\.[0-9]*[1-9])0+$/, '$1') + si[i].symbol
                }
            }
            return num.toString()
        }
        console.log(numberFormatter(1234, 2));//1.23千
        console.log(numberFormatter(12345, 2));//1.23万
        console.log(numberFormatter(123456, 2));//1.23十万
        console.log(numberFormatter(1234567, 2));//1.23百万
        console.log(numberFormatter(12345678, 2));//1.23千万

2. 大数字每隔三位加点

 function toThousandFilter(num) {
            return (+num || 0).toString().replace(/^-?\d+/g, m => m.replace(/(?=(?!\b)(\d{3})+$)/g, ','))
        }
        console.log(toThousandFilter(1234));//1,234
        console.log(toThousandFilter(12345));//12,345
        console.log(toThousandFilter(123456));//123,456
        console.log(toThousandFilter(1234567));//1,234,567
        console.log(toThousandFilter(12345678));//12,345,678

3.大小写转换

function uppercaseFirst(string) {
  return string.charAt(0).toUpperCase() + string.slice(1)
}
console.log(String)//string

4.uuid的生成

 getUUID = function () {
            const s = []
            var hexDigits = '0123456789abcdef'
            for (var i = 0; i < 36; i++) {
                s[i] = hexDigits.substr(Math.floor(Math.random() * 0x10), 1)
            }
            s[14] = '4'
            s[19] = hexDigits.substr((s[19] & 0x3) | 0x8, 1)
            s[8] = s[13] = s[18] = s[23] = '-'

            var uuid = s.join('')
            return uuid
        }
        console.log(getUUID());//38673f6b-bacc-4d9b-9330-dd97b7ae238f

4.复制内容到剪贴板

copyText = function (txt) {
  const input = document.createElement('input')
  input.value = txt
  document.body.appendChild(input)
  input.select()
  document.execCommand('Copy')
  document.body.removeChild(input)
}

这个请自己尝试,亲测有效
5.cookie清空

clearCookie = function () {
  var keys = document.cookie.match(/[^ =;]+(?=\=)/g)
  if (keys) {
    for (var i = keys.length; i--;)
    document.cookie = keys[i] + '=0;expires=' + new Date( 0).toUTCString()
  }
}

6,性能分析函数

window.onload = function() {
    setTimeout(function() {
        let t = performance.timing;
        console.log('DNS查询耗时 ：' + (t.domainLookupEnd - t.domainLookupStart).toFixed(0))
        console.log('TCP链接耗时 ：' + (t.connectEnd - t.connectStart).toFixed(0))
        console.log('request请求耗时 ：' + (t.responseEnd - t.responseStart).toFixed(0))
        console.log('解析dom树耗时 ：' + (t.domComplete - t.domInteractive).toFixed(0))
        console.log('白屏时间 ：' + (t.responseStart - t.navigationStart).toFixed(0))
        console.log('domready时间 ：' + (t.domContentLoadedEventEnd - t.navigationStart).toFixed(0))
        console.log('onload时间 ：' + (t.loadEventEnd - t.navigationStart).toFixed(0))
        if (t = performance.memory) {
            console.log('js内存使用占比：' +  (t.usedJSHeapSize / t.totalJSHeapSize * 100).toFixed(2) + '%')
        }
    })
}

7.点击全屏

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");
}

8.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");
}

9.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
    }
}

10.匹配身份证(15位或18位)

function isIdCardNo(num) {
　　num = num.toUpperCase();
        //身份证号码为15位或者18位，15位时全为数字，18位前17位为数字，最后一位是校验位，可能为数字或字符X。
　　if (!(/(^/d{15}$)|(^/d{17}([0-9]|X)$)/.test(num)))
　　{
　　　　alert('输入的身份证号长度不对，或者号码不符合规定！/n15位号码应全为数字，18位号码末位可以为数字或X。');
　　　　return false;
　　}
}

11.移动电话

function checkMobile(str) {
　　if (!(/^1[3|5|8][0-9]\d{4,8}$/.test(str))) {
　　　　return false;
　　}
　　return true;
}

12.判断输入是否是有效的电子邮件

function isemail(str) {
　　var result = str.match(/^\w+((-\w+)|(\.\w+))*\@[A-Za-z0-9]+((\.|-)[A-Za-z0-9]+)*\.[A-Za-z0-9]+$/);
　　if (result == null) return false;
　　　　return true;
　　}