好久沒寫簡書,今天看大神的代碼里面,好多封裝好的工具函數(shù),忍不住想偷師一下,所以在這里總結(jié)一下

1. 大數(shù)值轉(zhuǎn)換和保留n位有效數(shù)字

 function numberFormatter(num, digits) {
            const si = [
                { value: 1E13, symbol: '億億' },
                { value: 1E12, symbol: '萬億' },
                { value: 1E11, symbol: '千億' },
                { value: 1E10, symbol: '百億' },
                { value: 1E9, symbol: '十億' },
                { value: 1E8, symbol: '億' },
                { value: 1E7, symbol: '千萬' },
                { value: 1E6, symbol: '百萬' },
                { value: 1E5, symbol: '十萬' },
                { value: 1E4, symbol: '萬' },
                { 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));//1.23萬
        console.log(numberFormatter(123456, 2));//1.23十萬
        console.log(numberFormatter(1234567, 2));//1.23百萬
        console.log(numberFormatter(12345678, 2));//1.23千萬

2. 大數(shù)字每隔三位加點

 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.大小寫轉(zhuǎn)換

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.復(fù)制內(nèi)容到剪貼板

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

這個請自己嘗試,親測有效
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,性能分析函數(shù)

window.onload = function() {
    setTimeout(function() {
        let t = performance.timing;
        console.log('DNS查詢耗時 ：' + (t.domainLookupEnd - t.domainLookupStart).toFixed(0))
        console.log('TCP鏈接耗時 ：' + (t.connectEnd - t.connectStart).toFixed(0))
        console.log('request請求耗時 ：' + (t.responseEnd - t.responseStart).toFixed(0))
        console.log('解析dom樹耗時 ：' + (t.domComplete - t.domInteractive).toFixed(0))
        console.log('白屏?xí)r間 ：' + (t.responseStart - t.navigationStart).toFixed(0))
        console.log('domready時間 ：' + (t.domContentLoadedEventEnd - t.navigationStart).toFixed(0))
        console.log('onload時間 ：' + (t.loadEventEnd - t.navigationStart).toFixed(0))
        if (t = performance.memory) {
            console.log('js內(nèi)存使用占比：' +  (t.usedJSHeapSize / t.totalJSHeapSize * 100).toFixed(2) + '%')
        }
    })
}

7.點擊全屏

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

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("切換失敗,可嘗試Esc退出");
}

9.獲取瀏覽器信息

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.匹配身份證(15位或18位)

function isIdCardNo(num) {
　　num = num.toUpperCase();
        //身份證號碼為15位或者18位静尼，15位時全為數(shù)字块蚌，18位前17位為數(shù)字，最后一位是校驗位，可能為數(shù)字或字符X。
　　if (!(/(^/d{15}$)|(^/d{17}([0-9]|X)$)/.test(num)))
　　{
　　　　alert('輸入的身份證號長度不對，或者號碼不符合規(guī)定腹忽！/n15位號碼應(yīng)全為數(shù)字，18位號碼末位可以為數(shù)字或X砚作。');
　　　　return false;
　　}
}

11.移動電話

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

12.判斷輸入是否是有效的電子郵件

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;
　　}