Summary of 50+ Utility Functions in JavaScript

function isStatic(value) {
    return (
        typeof value === 'string' ||
        typeof value === 'number' ||
        typeof value === 'boolean' ||
        typeof value === 'undefined' ||
        value === null
    )
}

function isPrimitive(value) {
    return isStatic(value) || typeof value === 'symbol'
}

function isObject(value) {
    let type = typeof value;
    return value != null && (type == 'object' || type == 'function');
}

function isObjectLike(value) {
    return value != null && typeof value == 'object';
}

function getRawType(value) {
    return Object.prototype.toString.call(value).slice(8, -1)
}
// getoRawType([]) ⇒ Array

function isPlainObject(obj) {
    return Object.prototype.toString.call(obj) === '[object Object]'
}

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

//Mount isArray onto ArrayArray.isArray = Array.isArray || isArray;

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

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

function isNative(value) {
    return typeof value === 'function' && /native code/.test(value.toString())
}

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

function isLength(value) {
    return typeof value == 'number' && value > -1 && value % 1 == 0 && value <= Number.MAX_SAFE_INTEGER;
}

function isArrayLike(value) {
    return value != null && isLength(value.length) && !isFunction(value);
}

function isEmpty(value) {
    if (value == null) {
        return true;
    }
    if (isArrayLike(value)) {
        return !value.length;
    } else if (isPlainObject(value)) {
        for (let key in value) {
            if (hasOwnProperty.call(value, key)) {
                return false;
            }
        }
    }
    return false;
}

function cached(fn) {
    let cache = Object.create(null);
    return function cachedFn(str) {
        let hit = cache[str];
        return hit || (cache[str] = fn(str))
    }
}

let camelizeRE = /-(\w)/g;
function camelize(str) {
    return str.replace(camelizeRE, function(_, c) {
        return c ? c.toUpperCase() : '';
    })
}
//ab-cd-ef ==> abCdEf
//Use the memory function let _camelize = cached(camelize)

let hyphenateRE = /\B([AZ])/g;
function hyphenate(str){
    return str.replace(hyphenateRE, '-$1').toLowerCase()
}
//abCd ==> ab-cd
//Using the memoized function let _hyphenate = cached(hyphenate);

function capitalize(str) {
    return str.charAt(0).toUpperCase() + str.slice(1)
}
//abc ==> Abc
//Using the memoized function let _capitalize = cached(capitalize)

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

Object.assign = Object.assign || function() {
    if (arguments.length == 0) throw new TypeError('Cannot convert undefined or null to object');
    let target = arguments[0],
        args = Array.prototype.slice.call(arguments, 1),
        key;
    args.forEach(function(item) {
        for (key in item) {
            item.hasOwnProperty(key) && (target[key] = item[key])
        }
    })
    return target
}

let clone = Object.assign({}, target);

let clone = JSON.parse( JSON.stringify(target) )

function clone(value, deep) {
    if (isPrimitive(value)) {
        return value
    }
    if (isArrayLike(value)) { // is an array-like value = Array.prototype.slice.call(vall)
        return value.map(item => deep ? clone(item, deep) : item)
    } else if (isPlainObject(value)) { //is an object let target = {}, key;
        for (key in value) {
            value.hasOwnProperty(key) && ( target[key] = deep ? clone(value[key], value[key] ))
        }
    }
    let type = getRawType(value);
    switch(type) {
        case 'Date':
        case 'RegExp':
        case 'Error': value = new window[type](value); break;
    }
    return value
}

//The operating environment is the browser let inBrowser = typeof window !== 'undefined';
//The operating environment is WeChat let inWeex = typeof WXEnvironment !== 'undefined' && !!WXEnvironment.platform;
let weexPlatform = inWeex && WXEnvironment.platform.toLowerCase();
//Browser UA judgment 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;

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
    }
}

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)
}

function unique(arr){
    if(!isArrayLink(arr)){ //not an array-like object return arr
    }
    let result = []
    let objarr = []
    let obj = Object.create(null)

    arr.forEach(item => {
        if(isStatic(item)){//It is the raw data except symbol let key = item + '_' + getRawType(item);
            if(!obj[key]){
                obj[key] = true
                result.push(item)
            }
        }else{//reference type and symbol
            if (!objarr.includes(item)){
                objarr.push(item)
                result.push(item)
            }
        }
    })

    return result
}

window.Set = window.Set || (function () {
    function Set(arr) {
        this.items = arr ? unique(arr) : [];
        this.size = this.items.length; // Array size}
    Set.prototype = {
        add: function (value) {
            // Add an element. If the element already exists, skip it and return the Set structure itself.
            if (!this.has(value)) {
                this.items.push(value);
                this.size++;
            }
            return this;
        },
        clear: function () {
            // Clear all members, no return value.
            this.items = []
            this.size = 0
        },
        delete: function (value) {
            //Delete a value and return a Boolean value to indicate whether the deletion is successful.
            return this.items.some((v, i) => {
                if(v === value){
                    this.items.splice(i,1)
                    return true
                }
                return false
            })
        },
        has: function (value) {
            //Returns a Boolean value indicating whether the value is a member of the Set.
            return this.items.some(v => v === value)
        },
        values: function () {
            return this.items
        },
    }

    return Set;
}());

function repeat(str, n) {
    let res = '';
    while(n) {
        if(n % 2 === 1) {
            res += str;
        }
        if(n > 1) {
            str += str;
        }
        n >>= 1;
    }
    return res
};
//repeat('123',3) ==> 123123123

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

function dateStrForma(str, from, to){
    //'20190626' 'YYYYMMDD' 'YYYY year MM month DD day'
    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 year MM month DD day') ==> June 26, 2019 // dateStrForma('121220190626', '----YYYYMMDD', 'YYYY year MM month DD day') ==> June 26, 2019 // dateStrForma('20190626', 'YYYY year MM month DD day', 'YYYYMMDD') ==> 20190626

// You can also use regular expressions to achieve this //'2019-06-26'.replace(/(\d{4})year(\d{2})month(\d{2})day/, '$1-$2-$3') ==> 2019-06-26

function getPropByPath(obj, path, strict) {
      let tempObj = obj;
      path = path.replace(/\[(\w+)\]/g, '.$1'); //Convert [0] to .0
      path = path.replace(/^\./, ''); //Remove the leading .

      let keyArr = path.split('.'); // Cut according to . let i = 0;
      for (let len ​​= keyArr.length; i < len - 1; ++i) {
        if (!tempObj && !strict) break;
        let key = keyArr[i];
        if (key in tempObj) {
            tempObj = tempObj[key];
        } else {
            if (strict) {//Turn on strict mode, no corresponding key value found, throw an error throw new Error('please transfer a valid prop path to form item!');
            }
            break;
        }
      }
      return {
        o: tempObj, //original data k: keyArr[i], //key value v: tempObj ? tempObj[keyArr[i]] : null //value corresponding to the key value};
};

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"}

function downloadFile(filename, data) {
    let DownloadLink = document.createElement('a');
    if (DownloadLink) {
        document.body.appendChild(DownloadLink);
        DownloadLink.style = 'display: none';
        DownloadLink.download = filename;
        DownloadLink.href = data;
        if (document.createEvent) {
            let DownloadEvt = document.createEvent('MouseEvents');
            DownloadEvt.initEvent('click', true, false);
            DownloadLink.dispatchEvent(DownloadEvt);
        } else if (document.createEventObject) {
            DownloadLink.fireEvent('onclick');
        } else if (typeof DownloadLink.onclick == 'function') {
            DownloadLink.onclick();
        }
        document.body.removeChild(DownloadLink);
    }
}

function toFullScreen() {
    let elem = document.body;
    elem.webkitRequestFullScreen
    ? elem.webkitRequestFullScreen()
    : elem.mozRequestFullScreen
    ? elem.mozRequestFullScreen()
    : elem.msRequestFullscreen
    ? elem.msRequestFullscreen()
    : elem.requestFullScreen
    ? elem.requestFullScreen()
    : alert("The browser does not support full screen");
}

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("Switch failed, try to exit by pressing Esc");
}

window.requestAnimationFrame = window.requestAnimationFrame ||
    window.webkitRequestAnimationFrame ||
    window.mozRequestAnimationFrame ||
    window.msRequestAnimationFrame ||
    window.oRequestAnimationFrame ||
    function (callback) {
        //In order to make setTimeout as close to 60 frames per second as possible, window.setTimeout(callback, 1000 / 60);
    }
window.cancelAnimationFrame = window.cancelAnimationFrame ||
    window.webkitCancelAnimationFrame ||
    window.mozCancelAnimationFrame ||
    window.msCancelAnimationFrame ||
    window.oCancelAnimationFrame ||
    function (id) {
        //In order to make setTimeout as close to 60 frames per second as possible window.clearTimeout(id);
    }

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

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

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

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

Object.keys = Object.keys || function keys(object) {
    if (object === null || object === undefined) {
        throw new TypeError('Cannot convert undefined or null to object');
    }
    let result = [];
    if (isArrayLike(object) || isPlainObject(object)) {
        for (let key in object) {
            object.hasOwnProperty(key) && (result.push(key))
        }
    }
    return result;
}

Object.values ​​= Object.values ​​|| function values(object) {
    if (object === null || object === undefined) {
        throw new TypeError('Cannot convert undefined or null to object');
    }
    let result = [];
    if (isArrayLike(object) || isPlainObject(object)) {
        for (let key in object) {
            object.hasOwnProperty(key) && (result.push(object[key]))
        }
    }
    return result;
}

Array.prototype.fill = Array.prototype.fill || function fill(value, start, end) {
    let ctx = this
    let length = ctx.length;

    start = parseInt(start)
    if (isNaN(start)) {
        start = 0
    }else if (start < 0) {
        start = -start > length ? 0 : (length + start);
      }

      end = parseInt(end)
      if(isNaN(end) || end > length){
          end = length
      }else if (end < 0) {
        end += length;
    }

    while (start < end) {
        ctx[start++] = value;
    }
    return ctx;
}
//Array(3).fill(2) ===> [2, 2, 2]

Array.prototype.includes = Array.prototype.includes || function includes(value, start) {
    let ctx = this;
    let length = ctx.length;
    start = parseInt(start)
    if(isNaN(start)) {
        start = 0
    } else if (start < 0) {
        start = -start > length ? 0 : (length + start);
    }
    let index = ctx.indexOf(value);
    return index >= start;
}

Array.prototype.find = Array.prototype.find || function find(fn, ctx) {
    ctx = ctx || this;
    let result;
    ctx.some((value, index, arr), thisValue) => {
        return fn(value, index, arr) ? (result = value, true) : false
    })
    return result
}

Array.prototype.findIndex = Array.prototype.findIndex || function findIndex(fn, ctx){
    ctx = ctx || this

    let result;
    ctx.some((value, index, arr), thisValue) => {
        return fn(value, index, arr) ? (result = index, true) : false
    })

    return result
}

window.onload = function() {
    setTimeout(function() {
        let t = performance.timing;
        console.log('DNS query time:' + (t.domainLookupEnd - t.domainLookupStart).toFixed(0))
        console.log('TCP connection time:' + (t.connectEnd - t.connectStart).toFixed(0))
        console.log('request request time:' + (t.responseEnd - t.responseStart).toFixed(0))
        console.log('Time spent parsing the DOM tree:' + (t.domComplete - t.domInteractive).toFixed(0))
        console.log('White screen time:' + (t.responseStart - t.navigationStart).toFixed(0))
        console.log('domready time: ' + (t.domContentLoadedEventEnd - t.navigationStart).toFixed(0))
        console.log('onload time: ' + (t.loadEventEnd - t.navigationStart).toFixed(0))
        if (t = performance.memory) {
            console.log('js memory usage percentage:' + (t.usedJSHeapSize / t.totalJSHeapSize * 100).toFixed(2) + '%')
        }
    })
}

document.addEventListener('keydown', function(event) {
    return !(
        112 == event.keyCode || //Disable F1
        123 == event.keyCode || //Disable F12
        event.ctrlKey && 82 == event.keyCode || //Disable ctrl+R
        event.ctrlKey && 18 == event.keyCode || //Disable ctrl+N
        event.shiftKey && 121 == event.keyCode || //Disable shift+F10
        event.altKey && 115 == event.keyCode || //Disable alt+F4
        "A" == event.srcElement.tagName && event.shiftKey //Disable shift+click on tag a) || (event.returnValue = false)
});

['contextmenu', 'selectstart', 'copy'].forEach(function(ev) {
    document.addEventListener(ev, function(event) {
        return event.returnValue = false;
    })
});

function numAdd(num1, num2) {
    let baseNum, baseNum1, baseNum2;
    try {
        baseNum1 = num1.toString().split(".")[1].length;
    } catch (e) {
        baseNum1 = 0;
    }
    try {
        baseNum2 = num2.toString().split(".")[1].length;
    } catch (e) {
        baseNum2 = 0;
    }
    baseNum = Math.pow(10, Math.max(baseNum1, baseNum2));
    return (num1 * baseNum + num2 * baseNum) / baseNum;
};

function numSub(num1, num2) {
    let baseNum, baseNum1, baseNum2;
    let precision; // precision try {
        baseNum1 = num1.toString().split(".")[1].length;
    } catch (e) {
        baseNum1 = 0;
    }
    try {
        baseNum2 = num2.toString().split(".")[1].length;
    } catch (e) {
        baseNum2 = 0;
    }
    baseNum = Math.pow(10, Math.max(baseNum1, baseNum2));
    precision = (baseNum1 >= baseNum2) ? baseNum1 : baseNum2;
    return ((num1 * baseNum - num2 * baseNum) / baseNum).toFixed(precision);
};

function numMulti(num1, num2) {
    let baseNum = 0;
    try {
        baseNum += num1.toString().split(".")[1].length;
    } catch (e) {
    }
    try {
        baseNum += num2.toString().split(".")[1].length;
    } catch (e) {
    }
    return Number(num1.toString().replace(".", "")) * Number(num2.toString().replace(".", "")) / Math.pow(10, baseNum);
};

function numDiv(num1, num2) {
    let baseNum1 = 0, baseNum2 = 0;
    let baseNum3, baseNum4;
    try {
        baseNum1 = num1.toString().split(".")[1].length;
    } catch (e) {
        baseNum1 = 0;
    }
    try {
        baseNum2 = num2.toString().split(".")[1].length;
    } catch (e) {
        baseNum2 = 0;
    }
    with (Math) {
        baseNum3 = Number(num1.toString().replace(".", ""));
        baseNum4 = Number(num2.toString().replace(".", ""));
        return (baseNum3 / baseNum4) * pow(10, baseNum2 - baseNum1);
    }
};