這些JS工具函數(shù)夠你用到2020年底了
作者: maomin9761
本篇給大家介紹JS工具函數(shù),希望對你有所幫助?;畈欢嗾f,自己平時搜集的干貨函數(shù)奉上。
前言
活不多說,自己平時搜集的干貨函數(shù)奉上。
干貨函數(shù)
找出數(shù)字在數(shù)組中下一個相鄰的元素
- let i = "";
- let rr = [];
- const name = (n, arr1)=>{
- let num = Number(n);
- for (let i = 0; i < arr1.length; i++) {
- const element = arr1[i];
- if (element != num) {
- rr.push(num--);
- }
- }
- return rr.find((el) => {
- let newel = String(el);
- return arr1.includes(newel);
- })}
- let arr = ["2", "4", "6", "8", "10", "12", "14", "16", "18", "20", "22", "24", "27", "30", "33", "36", "42", "48", "54", "60"]
- console.log(name('5',arr)); //4
格式化時間
- /**
- * @param {number} time
- * @param {string} option
- * @returns {string}
- */
- function formatTime(time, option) {
- if (('' + time).length === 10) {
- time = parseInt(time) * 1000
- } else {
- time = +time
- }
- const d = new Date(time)
- const now = Date.now()
- const diff = (now - d) / 1000
- if (diff < 30) {
- return '剛剛'
- } else if (diff < 3600) {
- // less 1 hour
- return Math.ceil(diff / 60) + '分鐘前'
- } else if (diff < 3600 * 24) {
- return Math.ceil(diff / 3600) + '小時前'
- } else if (diff < 3600 * 24 * 2) {
- return '1天前'
- }
- if (option) {
- return parseTime(time, option)
- } else {
- return (
- d.getMonth() +
- 1 +
- '月' +
- d.getDate() +
- '日' +
- d.getHours() +
- '時' +
- d.getMinutes() +
- '分'
- )
- }
- }
解析時間
- /**
- * Parse the time to string
- * @param {(Object|string|number)} time
- * @param {string} cFormat
- * @returns {string | null}
- */
- function parseTime(time, cFormat) {
- if (arguments.length === 0 || !time) {
- return null
- }
- const format = cFormat || '{y}-{m}-k6zqhab033oa {h}:{i}:{s}'
- let date
- if (typeof time === 'object') {
- date = time
- } else {
- if ((typeof time === 'string')) {
- if ((/^[0-9]+$/.test(time))) {
- // support "1548221490638"
- time = parseInt(time)
- } else {
- // support safari
- // https://stackoverflow.com/questions/4310953/invalid-date-in-safari
- time = time.replace(new RegExp(/-/gm), '/')
- }
- }
- if ((typeof time === 'number') && (time.toString().length === 10)) {
- time = time * 1000
- }
- date = new Date(time)
- }
- const formatObj = {
- y: date.getFullYear(),
- m: date.getMonth() + 1,
- d: date.getDate(),
- h: date.getHours(),
- i: date.getMinutes(),
- s: date.getSeconds(),
- a: date.getDay()
- }
- const time_str = format.replace(/{([ymdhisa])+}/g, (result, key) => {
- const value = formatObj[key]
- // Note: getDay() returns 0 on Sunday
- if (key === 'a') { return ['日', '一', '二', '三', '四', '五', '六'][value ] }
- return value.toString().padStart(2, '0')
- })
- return time_str
- }
解析Url地址
- /**
- * @param {string} url
- * @returns {Object}
- */
- function param2Obj(url) {
- const search = decodeURIComponent(url.split('?')[1]).replace(/\+/g, ' ')
- if (!search) {
- return {}
- }
- const obj = {}
- const searchArr = search.split('&')
- searchArr.forEach(v => {
- const index = v.indexOf('=')
- if (index !== -1) {
- const name = v.substring(0, index)
- const val = v.substring(index + 1, v.length)
- obj[name] = val
- }
- })
- return obj
- }
合并兩個對象
- /**
- * Merges two objects, giving the last one precedence
- * @param {Object} target
- * @param {(Object|Array)} source
- * @returns {Object}
- */
- function objectMerge(target, source) {
- if (typeof target !== 'object') {
- target = {}
- }
- if (Array.isArray(source)) {
- return source.slice()
- }
- Object.keys(source).forEach(property => {
- const sourceProperty = source[property]
- if (typeof sourceProperty === 'object') {
- target[property] = objectMerge(target[property], sourceProperty)
- } else {
- target[property] = sourceProperty
- }
- })
- return target
- }
數(shù)組去重
- /**
- * @param {Array} arr
- * @returns {Array}
- */
- function uniqueArr(arr) {
- return Array.from(new Set(arr))
- }
防抖
- /**
- * @param {Function} func
- * @param {number} wait
- * @param {boolean} immediate
- * @return {*}
- */
- function debounce(func, wait, immediate) {
- let timeout, args, context, timestamp, result
- const later = function() {
- // 據(jù)上一次觸發(fā)時間間隔
- const last = +new Date() - timestamp
- // 上次被包裝函數(shù)被調(diào)用時間間隔 last 小于設定時間間隔 wait
- if (last < wait && last > 0) {
- timeout = setTimeout(later, wait - last)
- } else {
- timeout = null
- // 如果設定為immediate===true,因為開始邊界已經(jīng)調(diào)用過了此處無需調(diào)用
- if (!immediate) {
- result = func.apply(context, args)
- if (!timeout) context = args = null
- }
- }
- }
- return function(...args) {
- context = this
- timestamp = +new Date()
- const callNow = immediate && !timeout
- // 如果延時不存在,重新設定延時
- if (!timeout) timeout = setTimeout(later, wait)
- if (callNow) {
- result = func.apply(context, args)
- context = args = null
- }
- return result
- }
- }
簡易搜索
- <!DOCTYPE html>
- <html lang="en">
- <head>
- <meta charset="UTF-8">
- <meta name="viewport" content="width=device-width, initial-scale=1.0">
- <title>Document</title>
- </head>
- <body>
- <input type="text" id="int">
- </body>
- <script>
- let list = ["示例1","示例12","示例5","示例56"];
- document.querySelector('#int').onchange=function(e){
- console.log(search(e.target.value));
- }
- function search(val) {
- if (val) {
- return list.filter(function (item) {
- return Object.keys(item).some(function (key) {
- return String(item[key]).toLowerCase().indexOf(val) > -1
- })
- })
- }
- return list
- }
- </script>
- </html>
將秒化為時分秒
- function formateSeconds (endTime) {
- let secondTime = parseInt(endTime); //將傳入的秒的值轉(zhuǎn)化為Number
- let min = 0; // 初始化分
- let h = 0; // 初始化小時
- let result = "";
- if (secondTime > 60) {
- //如果秒數(shù)大于60,將秒數(shù)轉(zhuǎn)換成整數(shù)
- min = parseInt(secondTime / 60); //獲取分鐘,除以60取整數(shù),得到整數(shù)分鐘
- secondTime = parseInt(secondTime % 60); //獲取秒數(shù),秒數(shù)取佘,得到整數(shù)秒數(shù)
- if (min > 60) {
- //如果分鐘大于60,將分鐘轉(zhuǎn)換成小時
- h = parseInt(min / 60); //獲取小時,獲取分鐘除以60,得到整數(shù)小時
- min = parseInt(min % 60); //獲取小時后取佘的分,獲取分鐘除以60取佘的分
- }
- }
- result = `${h.toString().padStart(2, "0")}:${min.toString().padStart(2, "0")}:${secondTime.toString().padStart(2, "0")}`;
- return result;
- }
- 將時分秒化為秒
將時分秒化為秒
- function formSeconds (times) {
- let arr = times.split(":");
- let s = arr[2];
- let m = arr[1];
- let h = arr[0];
- let m1 = m<10?m.replace(/\b(0+)/gi,""):m;
- let h1 = h<10?h.replace(/\b(0+)/gi,""):h;
- return m1*60+Number(h1)+Number(s)
- }
對象深層遍歷
- var obj = {
- a:{
- b:{
- c:"maomin"
- }
- }
- }
- const safeGet = (obj, path) => {
- try {
- return path.split('.').reduce((o, k) => o[k], obj)
- } catch (e) {
- return undefined
- }
- }
- console.log(safeGet(obj,'a.b.c'));// maomin
帶有分割符的字符串轉(zhuǎn)化成一個n維數(shù)組
- var str = "A-2-12";
- var str1 = str.split('-');
- var arr = str1.reverse().reduce((pre,cur,i) => {
- if(i==0)
- { pre.push(cur)
- return pre
- }
- return [cur,pre]
- },[])
- console.log(arr) // ["A"["B",["C"]]]
獲取時間戳
- function thedata(d){
- return d.replace(/\-/g, "\/")
- }
- var serverTime = parseInt(new Date(thedata('2020-08-12 15:52:11')).valueOf());
- console.log(serverTime); // 1597218731000,獲取到時間戳
對象深拷貝
- function deepClone(target) {
- // 定義一個變量
- let result;
- // 如果當前需要深拷貝的是一個對象的話
- if (typeof target === 'object') {
- // 如果是一個數(shù)組的話
- if (Array.isArray(target)) {
- result = []; // 將result賦值為一個數(shù)組,并且執(zhí)行遍歷
- for (let i in target) {
- // 遞歸克隆數(shù)組中的每一項
- result.push(deepClone(target[i]))
- }
- // 判斷如果當前的值是null的話;直接賦值為null
- } else if(target===null) {
- result = null;
- // 判斷如果當前的值是一個RegExp對象的話,直接賦值
- } else if(target.constructor===RegExp){
- result = target;
- }else {
- // 否則是普通對象,直接for in循環(huán),遞歸賦值對象的所有值
- result = {};
- for (let i in target) {
- result[i] = deepClone(target[i]);
- }
- }
- // 如果不是對象的話,就是基本數(shù)據(jù)類型,那么直接賦值
- } else {
- result = target;
- }
- // 返回最終結(jié)果
- return result;
- }
簡易版對象拷貝
- function copy(obj) {
- if(typeof obj == "object") { //判斷是否復雜類型
- var result = obj.constructor == Array ? [] : {};//判斷數(shù)組類型或是object,數(shù)組即result=[],object即result={}
- for(let i in obj) {
- result[i] = typeof obj[i] == "object" ? copy(obj[i]) : obj[i]//判斷數(shù)據(jù)每一項是否是object
- }
- } else {
- var result = obj //基本類型直接拷貝
- }
- return result;
- }
實現(xiàn)一個模板引擎
- function render(template, data) {
- const reg = /\{\{(\w+)\}\}/; // 模板字符串正則
- if (reg.test(template)) { // 判斷模板里是否有模板字符串
- const name = reg.exec(template)[1]; // 查找當前模板里第一個模板字符串的字段
- template = template.replace(reg, data[name]); // 將第一個模板字符串渲染
- return render(template, data); // 遞歸的渲染并返回渲染后的結(jié)構(gòu)
- }
- return template; // 如果模板沒有模板字符串直接返回
- }
- let template = '我是{{name}},年齡{{age}},性別{{sex}}';
- let data = {
- name: '姓名',
- age: 18
- }
- render(template, data); // 我是姓名,年齡18,性別undefined
節(jié)流
- // ①定時器實現(xiàn)
- const throttle = (fn,delay = 500) =>{
- let flag = true;
- return (...args) => {
- if(!flag) return;
- flag = false;
- setTimeout(() => {
- fn.apply(this,args);
- flag = true;
- },delay);
- };
- }
- // ②時間戳實現(xiàn)
- const throttle = (fn,delay = 500) => {
- let preTime = Date.now();
- return (...args) => {
- const nowTime = Date.now();
- if(nowTime - preTime >= delay){
- preTime = Date.now();
- fn.apply(this,args);
- }
- }
- }
封裝fetch
- /**
- * 封裝fetch函數(shù),用Promise做回調(diào)
- * @type {{get: (function(*=)), post: (function(*=, *=))}}
- */
- const fetchUtil = {
- get: (url) => {
- return new Promise((resolve, reject) => {
- fetch(url, {
- method: 'GET',
- headers: {
- 'Content-Type': 'application/x-www-form-urlencoded',
- }
- }).then((response) => response.json()).then(response => {
- resolve(response);
- }).catch(err => {
- reject(new Error(err));
- });
- });
- },
- post: (url, params) => {
- return new Promise((resolve, reject) => {
- fetch(url, {
- method: 'POST',
- headers: {
- 'Content-Type': 'application/x-www-form-urlencoded',
- },
- body: params
- }).then((response) => response.json()).then(response => {
- resolve(response);
- }).catch(err => {
- reject(new Error(err));
- });
- });
- }
- };
判斷瀏覽器環(huán)境
- function getSystem(){
- const mac = /mac/i,
- linux = /linux/i,
- win = /win/i;
- const platform = navigator.platform.toLowerCase();
- if(mac.test(platform)){
- return 'MAC';
- } else if(win.test(platform)){
- return 'WIN';
- } else if(linux.test(platform)){
- return 'Linux';
- }
- return undefined;
- }
- const browser = {
- versions:function(){
- let ret = 'xxSys';
- const u = navigator.userAgent;
- const isMobile = !!u.match(/AppleWebKit.*Mobile.*/),
- ios = !!u.match(/\(i[^;]+;( U;)? CPU.+Mac OS X/),
- android = u.indexOf('Android') > -1 || u.indexOf('Adr') > -1;
- if(isMobile){
- if(ios) return 'IOS';
- if(android) return 'Android';
- } else {
- ret = getSystem() || ret;
- }
- return ret;
- }(),
- };
定義數(shù)組內(nèi)部對象形式
- const objArrtransArr = (olddata, oldval, oldname)=>{
- const newArr = [];
- olddata.forEach(item => {
- // 定義數(shù)組內(nèi)部對象形式
- let obj = {};
- obj.value = item[oldval];
- obj.name = item[oldname];
- // 將對象數(shù)據(jù)推到數(shù)組中
- newArr.push(obj);
- });
- return newArr;
- }
解析html字符串
- function (htmlobj) {
- var el = document.createElement('div');
- el.innerHTML = htmlobj;
- var tags = el.getElementsByTagName('img');
- var text = tags[0].getAttribute("src");
- return text;
- }
判斷瀏覽器是否支持攝像頭
- function videoCheck () {
- var deviceList = [];
- navigator.mediaDevices
- .enumerateDevices()
- .then(devices => {
- devices.forEach(device => {
- deviceList.push(device.kind);
- });
- if (deviceList.indexOf("videoinput") == "-1") {
- console.info("沒有攝像頭");
- return false;
- } else {
- console.info("有攝像頭");
- }
- })
- .catch(function(err) {
- alert(err.name + ": " + err.message);
- });
- }
回文算法
- //忽略標點符號、大小寫和空格,正著讀和反著讀一模一樣。
- nction made(str) {
- var str1 = str.toLowerCase(); //先將字符串全部轉(zhuǎn)換為小寫
- var reg = /[\W\_]/g; // 刪除所有非字母數(shù)字字符和下劃線
- var str2 = str1.replace(reg, ""); // 去掉非字母和非數(shù)字
- var str3 = str2.split(""); // 字符串分隔成數(shù)組
- var str4 = str3.reverse(); // 反轉(zhuǎn)數(shù)組中的元素
- var str5 = str4.join(""); // 反轉(zhuǎn)后的數(shù)組轉(zhuǎn)化為字符串
- return str2 === str5;
持續(xù)更新...
責任編輯:姜華
來源:
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