20 个叹为观止的 JavaScript 一行代码

const cookie = name => `; ${document.cookie}`.split(`; ${name}=`).pop().split(';').shift();
cookie('_ga');// Result: "GA1.2.1929736587.1601974046"

const rgbToHex = (r, g, b) =>"#" + ((1 << 24) + (r << 16) + (g << 8) + b).toString(16).slice(1);
rgbToHex(0, 51, 255);// Result: #0033ff`

const copyToClipboard = (text) => navigator.clipboard.writeText(text);
copyToClipboard("Hello World");

const isDateValid = (...val) => !Number.isNaN(new Date(...val).valueOf());
isDateValid("December 17, 1995 03:24:00");// Result: true

const dayOfYear = (date) =>Math.floor((date - new Date(date.getFullYear(), 0, 0)) / 1000 / 60 / 60 / 24);
dayOfYear(new Date());// Result: 272

const capitalize = str => str.charAt(0).toUpperCase() + str.slice(1)
capitalize("follow for more")// Result: Follow for more

const dayDif = (date1, date2) => Math.ceil(Math.abs(date1.getTime() - date2.getTime()) / 86400000)
dayDif(new Date("2020-10-21"), new Date("2021-10-22"))// Result: 366

const clearCookies = document.cookie.split(';').forEach(cookie => document.cookie = cookie.replace(/^ +/, '').replace(/=.\*/, `=;expires=${new Date(0).toUTCString()};path=/`));

const randomHex = () => `#${Math.floor(Math.random() * 0xffffff).toString(16).padEnd(6, "0")}`;
console.log(randomHex());// Result: #92b008

const removeDuplicates = (arr) => [...new Set(arr)];
console.log(removeDuplicates([1, 2, 3, 3, 4, 4, 5, 5, 6]));// Result: [ 1, 2, 3, 4, 5, 6 ]

const getParameters = (URL) => {URL = JSON.parse('{"' + decodeURI(URL.split("?")[1]).replace(/"/g, '\\"').replace(/&/g, '","').replace(/=/g, '":"') +'"}');return JSON.stringify(URL);};
getParameters(window.location)// Result: { search : "easy", page : 3 }

const timeFromDate = date => date.toTimeString().slice(0, 8);
console.log(timeFromDate(new Date(2021, 0, 10, 17, 30, 0)));// Result: "17:30:00"

//通过数据%2来判断并返回布尔类型const isEven = num => num % 2 === 0;
console.log(isEven(2));// Result: True

const average = (...args) => args.reduce((a, b) => a + b) / args.length;
average(1, 2, 3, 4);// Result: 2.5

//通过将x、y设置为0来实现const goToTop = () => window.scrollTo(0, 0);
goToTop();

const reverse = str => str.split('').reverse().join('');
reverse('hello world');// Result: 'dlrow olleh'

//通过对数组长度判断来确定是否为空const isNotEmpty = arr => Array.isArray(arr) && arr.length > 0;
isNotEmpty([1, 2, 3]);// Result: true

const getSelectedText = () => window.getSelection().toString();
getSelectedText();

const shuffleArray = (arr) => arr.sort(() => 0.5 - Math.random());
console.log(shuffleArray([1, 2, 3, 4]));// Result: [ 1, 4, 3, 2 ]

const isDarkMode = window.matchMedia && window.matchMedia('(prefers-color-scheme: dark)').matches
console.log(isDarkMode) // Result: True or False