本文已經過原作者 Orkhan Jafarov 授權翻譯。
1. 生成一個帶有隨機數的列表Array.from({ length: 1000 }, Math.random)// [ 0.6163093133259432, 0.8877401276499153, 0.4094354756035987, ...] - 1000 items
2.生成一個帶有數字的列表
Array.from({ length: 1000 }, (v, i) => i)// [0, 1, 2, 3, 4, 5, 6....999]
3. RGB→轉換為十六進位制const rgb2hex = ([r, g, b]) => `#${(1 << 24) + (r << 16) + (g << 8) + b}`.toString(16).substr(1);rgb2hex([76, 11, 181]);// #4c0bb5
4. 轉換十六進位制→RGB
怎麼把它轉換回去?這是實現該目標的一種好方法。
const hex2rgb = hex => [1, 3, 5].map((h) => parseInt(hex.substring(h, h + 2), 16));hex2rgb("#4c0bb5");// [76, 11, 181]
5.奇數或偶數
使用 位 運算的方式:
const value = 232; if (value & 1) console.log("odd");else console.log("even");// even
6.檢查有效的 URLconst isValidURL = (url) => { try { new URL(url); return true; } catch (error) { return false; }}isValidURL('https://segmentfault.com/u/minnanitkong/articles')// trueisValidURL("https//invalidto");// false
7.距離過去到現在時間表示
有時我們需要列印6分鐘前的日期,但不希望很大的庫來完成。這裡有一個小片段可以做到這一點:
const fromAgo = (date) => { const ms = Date.now() - date.getTime(); const seconds = Math.round(ms / 1000); const minutes = Math.round(ms / 60000); const hours = Math.round(ms / 3600000); const days = Math.round(ms / 86400000); const months = Math.round(ms / 2592000000); const years = Math.round(ms / 31104000000); switch (true) { case seconds < 60: return `${seconds} second(s) ago"`; case minutes < 60: return `${minutes} minute(s) ago"`; case hours < 24: return `${hours} hour(s) ago"`; case days < 30: return `${days} day(s) ago`; case months < 12: return `${months} month(s) ago`; default: return `${years} year(s) ago`; }};const createdAt = new Date(2021, 0, 5);fromAgo(createdAt); // 14 day(s) ago;
8. 用引數生成路徑我們在處理路線/路徑時常做很多工作,我們總是需要對其進行操作。當我們需要生成帶有引數的路徑以將瀏覽器推送到那裡時,generatePath 可以幫助我們!
const generatePath = (path, obj) => path.replace(/(:[a-z]+)/g, (v) => obj[v.substr(1)]);const route = "/app/:page/:id";generatePath(route, { page: "products", id: 85,});// /app/products/123
9.從路徑獲取引數
const getPathParams = (path, pathMap, serializer) => { path = path.split("/"); pathMap = pathMap.split("/"); return pathMap.reduce((acc, crr, i) => { if (crr[0] === ":") { const param = crr.substr(1); acc[param] = serializer && serializer[param] ? serializer[param](path[i]) : path[i]; } return acc; }, {});};getPathParams("/app/products/123", "/app/:page/:id");// { page: 'products', id: '123' }getPathParams("/items/2/id/8583212", "/items/:category/id/:id", { category: v => ['Car', 'Mobile', 'Home'][v], id: v => +v});// { category: 'Home', id: 8583212 }
10.用查詢字串生成路徑const getQueryParams = url => url.match(/([^?=&]+)(=([^&]*))/g).reduce((total, crr) => { const [key, value] = crr.split("="); total[key] = value; return total; }, {});getQueryParams("/user?name=Orkhan&age=30");// { name: 'Orkhan', age: '30' }
我是小智,我要去刷碗了,我們下期見~
原文:https://dev.to/11-javascript-tips-and-tricks-to-code-like-a-superhero-vol-2-mp6
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