這篇文章主要為大家展示了“如何使用ES6解決實(shí)際問(wèn)題”,內(nèi)容簡(jiǎn)而易懂,條理清晰,希望能夠幫助大家解決疑惑,下面讓小編帶領(lǐng)大家一起研究并學(xué)習(xí)一下“如何使用ES6解決實(shí)際問(wèn)題”這篇文章吧。
1.如何隱藏指定的所有元素?
const hide = (...el) => [...el].forEach(e => (e.style.display = 'none')); // Example hide(document.querySelectorAll('img')); // Hides all <img> elements on the page
2.如何檢查元素是否具有指定的類?
const hasClass = (el, className) => el.classList.contains(className); // Example hasClass(document.querySelector('p.special'), 'special'); // true
3.如何為元素切換類?
const toggleClass = (el, className) => el.classList.toggle(className); // Example toggleClass(document.querySelector('p.special'), 'special'); // The paragraph will not have the 'special' class anymore
這里使用了classList.toggle()方法
toggle( String [, force] )
當(dāng)只有一個(gè)參數(shù)時(shí):切換類值;也就是說(shuō),即如果類值存在,則刪除它并返回 false,如果不存在,則添加它并返回 true。
當(dāng)存在第二個(gè)參數(shù)時(shí):若第二個(gè)參數(shù)的執(zhí)行結(jié)果為 true,則添加指定的類值,若執(zhí)行結(jié)果為 false,則刪除它。
4.如何獲取當(dāng)前頁(yè)面的滾動(dòng)位置?
const getScrollPosition = (el = window) => ({ x: el.pageXOffset !== undefined ? el.pageXOffset : el.scrollLeft, y: el.pageYOffset !== undefined ? el.pageYOffset : el.scrollTop }); // Example getScrollPosition(); // {x: 0, y: 200}
5.如何平滑滾動(dòng)到頁(yè)面頂部?
const scrollToTop = () => { const c = document.documentElement.scrollTop || document.body.scrollTop; if (c > 0) { window.requestAnimationFrame(scrollToTop); window.scrollTo(0, c - c / 8); } }; // Example scrollToTop();
遞歸的方法不斷調(diào)用使用scrollToTop(),requestAnimationFrame方法告訴瀏覽器——你希望執(zhí)行一個(gè)動(dòng)畫(huà),并且要求瀏覽器在下次重繪之前調(diào)用指定的回調(diào)函數(shù)更新動(dòng)畫(huà)。它的回調(diào)函數(shù)執(zhí)行次數(shù)通常與瀏覽器屏幕刷新次數(shù)相匹配,所以效果會(huì)比較平滑。
獲取當(dāng)前頁(yè)面滾動(dòng)條縱坐標(biāo)的位置:document.body.scrollTop與document.documentElement.scrollTop
獲取當(dāng)前頁(yè)面滾動(dòng)條橫坐標(biāo)的位置:document.body.scrollLeft與document.documentElement.scrollLeft
6.如何檢查父元素是否包含子元素?
const elementContains = (parent, child) => parent !== child && parent.contains(child); // Examples elementContains(document.querySelector('head'), document.querySelector('title')); // true elementContains(document.querySelector('body'), document.querySelector('body')); // false
7.如何檢查指定的元素在視口中是否可見(jiàn)?
const elementIsVisibleInViewport = (el, partiallyVisible = false) => { const { top, left, bottom, right } = el.getBoundingClientRect(); const { innerHeight, innerWidth } = window; return partiallyVisible ? ((top > 0 && top < innerHeight) || (bottom > 0 && bottom < innerHeight)) && ((left > 0 && left < innerWidth) || (right > 0 && right < innerWidth)) : top >= 0 && left >= 0 && bottom <= innerHeight && right <= innerWidth; }; // Examples elementIsVisibleInViewport(el); // (not fully visible) elementIsVisibleInViewport(el, true); // (partially visible)
傳入partiallyVisible參數(shù),區(qū)分判斷是是部分可見(jiàn)還是全部可見(jiàn)。
Element.getBoundingClientRect()方法返回元素的大小及其相對(duì)于視口的位置。
8.如何獲取元素中的所有圖像?
const getImages = (el, includeDuplicates = false) => { const images = [...el.getElementsByTagName('img')].map(img => img.getAttribute('src')); return includeDuplicates ? images : [...new Set(images)]; }; // Examples getImages(document, true); // ['image1.jpg', 'image2.png', 'image1.png', '...'] getImages(document, false); // ['image1.jpg', 'image2.png', '...']
9.如何確定設(shè)備是移動(dòng)設(shè)備還是臺(tái)式機(jī)/筆記本電腦?
const detectDeviceType = () => /Android|webOS|iPhone|iPad|iPod|BlackBerry|IEMobile|Opera Mini/i.test(navigator.userAgent) ? 'Mobile' : 'Desktop'; // Example detectDeviceType(); // "Mobile" or "Desktop"
10.如何獲取當(dāng)前URL
const currentURL = () => window.location.href; // Example currentURL(); // 'https://google.com'
11.如何創(chuàng)建包含當(dāng)前URL參數(shù)的對(duì)象?
const getURLParameters = url => (url.match(/([^?=&]+)(=([^&]*))/g) || []).reduce( (a, v) => ((a[v.slice(0, v.indexOf('='))] = v.slice(v.indexOf('=') + 1)), a), {} ); // Examples getURLParameters('http://url.com/page?n=Adam&s=Smith'); // {n: 'Adam', s: 'Smith'} getURLParameters('google.com'); // {}
12.如何將一組表單元素編碼為對(duì)象?
const formToObject = form => Array.from(new FormData(form)).reduce( (acc, [key, value]) => ({ ...acc, [key]: value }), {} ); // Example formToObject(document.querySelector('#form')); // { email: 'test@email.com', name: 'Test Name' }
Array.from方法用于將兩類對(duì)象轉(zhuǎn)為真正的數(shù)組。類似數(shù)組的對(duì)象(array-like object)和可遍歷(iterable)的對(duì)象(包括 ES6 新增的數(shù)據(jù)結(jié)構(gòu) Set 和 Map)。
reducer 函數(shù)接收4個(gè)參數(shù):
Accumulator (acc) (累計(jì)器)
Current Value (cur) (當(dāng)前值)
Current Index (idx) (當(dāng)前索引)
Source Array (src) (源數(shù)組)
13.如何從對(duì)象中檢索出給定的一組屬性?
const get = (from, ...selectors) => [...selectors].map(s => s .replace(/\[([^\[\]]*)\]/g, '.$1.') .split('.') .filter(t => t !== '') .reduce((prev, cur) => prev && prev[cur], from) ); const obj = { selector: { to: { val: 'val to select' } }, target: [1, 2, { a: 'test' }] }; // Example get(obj, 'selector.to.val', 'target[0]', 'target[2].a'); // ['val to select', 1, 'test']
14.延遲調(diào)用提供的函數(shù)(以毫秒為單位)
const delay = (fn, wait, ...args) => setTimeout(fn, wait, ...args); delay( function(text) { console.log(text); }, 1000, 'later' ); // Logs 'later' after one second.
15.如何在給定元素上觸發(fā)特定事件,并可選地傳遞自定義數(shù)據(jù)?
const triggerEvent = (el, eventType, detail) => el.dispatchEvent(new CustomEvent(eventType, { detail })); // Examples triggerEvent(document.getElementById('myId'), 'click'); triggerEvent(document.getElementById('myId'), 'click', { username: 'bob' });
構(gòu)造方法 CustomerEvent() 創(chuàng)建一個(gè)新的 CustomEvent 對(duì)象。
CustomEvent 事件是由程序創(chuàng)建的,可以有任意自定義功能的事件。
16.如何從元素中移除事件偵聽(tīng)器?
const off = (el, evt, fn, opts = false) => el.removeEventListener(evt, fn, opts); const fn = () => console.log('!'); document.body.addEventListener('click', fn); off(document.body, 'click', fn); // no longer logs '!' upon clicking on the page
17.將給定的毫秒數(shù)轉(zhuǎn)換為可讀格式
const formatDuration = ms => { if (ms < 0) ms = -ms; const time = { day: Math.floor(ms / 86400000), hour: Math.floor(ms / 3600000) % 24, minute: Math.floor(ms / 60000) % 60, second: Math.floor(ms / 1000) % 60, millisecond: Math.floor(ms) % 1000 }; return Object.entries(time) .filter(val => val[1] !== 0) .map(([key, val]) => `${val} ${key}${val !== 1 ? 's' : ''}`) .join(', '); }; // Examples formatDuration(1001); // '1 second, 1 millisecond' formatDuration(34325055574); // '397 days, 6 hours, 44 minutes, 15 seconds, 574 milliseconds'
18.如何得到兩個(gè)日期之間的差異(以天為單位)
const getDaysDiffBetweenDates = (dateInitial, dateFinal) => (dateFinal - dateInitial) / (1000 * 3600 * 24); // Example getDaysDiffBetweenDates(new Date('2017-12-13'), new Date('2017-12-22')); // 9
19.如何對(duì)傳遞的URL發(fā)出GET請(qǐng)求
const httpGet = (url, callback, err = console.error) => { const request = new XMLHttpRequest(); request.open('GET', url, true); request.onload = () => callback(request.responseText); request.onerror = () => err(request); request.send(); }; httpGet( 'https://jsonplaceholder.typicode.com/posts/1', console.log ); // Logs: {"userId": 1, "id": 1, "title": "sample title", "body": "my text"}
20.如何對(duì)傳遞的URL發(fā)出POST請(qǐng)求?
const httpPost = (url, data, callback, err = console.error) => { const request = new XMLHttpRequest(); request.open('POST', url, true); request.setRequestHeader('Content-type', 'application/json; charset=utf-8'); request.onload = () => callback(request.responseText); request.onerror = () => err(request); request.send(data); }; const newPost = { userId: 1, id: 1337, title: 'Foo', body: 'bar bar bar' }; const data = JSON.stringify(newPost); httpPost( 'https://jsonplaceholder.typicode.com/posts', data, console.log ); // Logs: {"userId": 1, "id": 1337, "title": "Foo", "body": "bar bar bar"}
21. 如何為指定的選擇器創(chuàng)建具有指定范圍、步驟和持續(xù)時(shí)間的計(jì)數(shù)器?
const counter = (selector, start, end, step = 1, duration = 2000) => { let current = start, _step = (end - start) * step < 0 ? -step : step, timer = setInterval(() => { current += _step; document.querySelector(selector).innerHTML = current; if (current >= end) document.querySelector(selector).innerHTML = end; if (current >= end) clearInterval(timer); }, Math.abs(Math.floor(duration / (end - start)))); return timer; }; // Example counter('#my-id', 1, 1000, 5, 2000); // Creates a 2-second timer for the element with id="my-id"
22.如何將字符串復(fù)制到剪貼板
const copyToClipboard = str => { const el = document.createElement('textarea'); el.value = str; el.setAttribute('readonly', ''); el.style.position = 'absolute'; el.style.left = '-9999px'; document.body.appendChild(el); const selected = document.getSelection().rangeCount > 0 ? document.getSelection().getRangeAt(0) : false; el.select(); document.execCommand('copy'); document.body.removeChild(el); if (selected) { document.getSelection().removeAllRanges(); document.getSelection().addRange(selected); } }; // Example copyToClipboard('Lorem ipsum'); // 'Lorem ipsum' copied to clipboard.
document.getSelection()返回一個(gè) Selection 對(duì)象,表示用戶選擇的文本范圍或光標(biāo)的當(dāng)前位置。
23.判斷頁(yè)面的瀏覽器選項(xiàng)卡是否聚焦
const isBrowserTabFocused = () => !document.hidden; // Example isBrowserTabFocused(); // true
24.如果不存在目錄,則如何創(chuàng)建
const fs = require('fs'); const createDirIfNotExists = dir => (!fs.existsSync(dir) ? fs.mkdirSync(dir) : undefined); // Example createDirIfNotExists('test'); // creates the directory
以上是“如何使用ES6解決實(shí)際問(wèn)題”這篇文章的所有內(nèi)容,感謝各位的閱讀!相信大家都有了一定的了解,希望分享的內(nèi)容對(duì)大家有所幫助,如果還想學(xué)習(xí)更多知識(shí),歡迎關(guān)注創(chuàng)新互聯(lián)成都網(wǎng)站設(shè)計(jì)公司行業(yè)資訊頻道!
另外有需要云服務(wù)器可以了解下創(chuàng)新互聯(lián)scvps.cn,海內(nèi)外云服務(wù)器15元起步,三天無(wú)理由+7*72小時(shí)售后在線,公司持有idc許可證,提供“云服務(wù)器、裸金屬服務(wù)器、高防服務(wù)器、香港服務(wù)器、美國(guó)服務(wù)器、虛擬主機(jī)、免備案服務(wù)器”等云主機(jī)租用服務(wù)以及企業(yè)上云的綜合解決方案,具有“安全穩(wěn)定、簡(jiǎn)單易用、服務(wù)可用性高、性價(jià)比高”等特點(diǎn)與優(yōu)勢(shì),專為企業(yè)上云打造定制,能夠滿足用戶豐富、多元化的應(yīng)用場(chǎng)景需求。
網(wǎng)站標(biāo)題:如何使用ES6解決實(shí)際問(wèn)題-創(chuàng)新互聯(lián)
轉(zhuǎn)載來(lái)源:http://www.rwnh.cn/article22/cesojc.html
成都網(wǎng)站建設(shè)公司_創(chuàng)新互聯(lián),為您提供品牌網(wǎng)站設(shè)計(jì)、App開(kāi)發(fā)、營(yíng)銷(xiāo)型網(wǎng)站建設(shè)、網(wǎng)站營(yíng)銷(xiāo)、做網(wǎng)站、面包屑導(dǎo)航
聲明:本網(wǎng)站發(fā)布的內(nèi)容(圖片、視頻和文字)以用戶投稿、用戶轉(zhuǎn)載內(nèi)容為主,如果涉及侵權(quán)請(qǐng)盡快告知,我們將會(huì)在第一時(shí)間刪除。文章觀點(diǎn)不代表本網(wǎng)站立場(chǎng),如需處理請(qǐng)聯(lián)系客服。電話:028-86922220;郵箱:631063699@qq.com。內(nèi)容未經(jīng)允許不得轉(zhuǎn)載,或轉(zhuǎn)載時(shí)需注明來(lái)源: 創(chuàng)新互聯(lián)
猜你還喜歡下面的內(nèi)容