当我们需要一个唯一id时,通过Math.random创建一个随机字符串简直不要太方便噢!!!
const randomString = () => Math.random().toString(36).slice(2)
randomString() // gi1qtdego0b
randomString() // f3qixv40mot
randomString() // eeelv1pm3ja
解决XSS方法之一就是转义HTML。
const escape = (str) => str.replace(/[&<>"']/g, (m) => ({ '&': '&', '<': '<', '>': '>', '"': '"', "'": ''' }[m]))
escape('Hi Medium.')
// <div class="medium">Hi Medium.</div>
const uppercaseWords = (str) => str.replace(/^(.)|\s+(.)/g, (c) => c.toUpperCase())
uppercaseWords('hello world'); // 'Hello World'
const toCamelCase = (str) => str.trim().replace(/[-_\s]+(.)?/g, (_, c) => (c ? c.toUpperCase() : ''));
toCamelCase('background-color'); // backgroundColor
toCamelCase('-webkit-scrollbar-thumb'); // WebkitScrollbarThumb
toCamelCase('_hello_world'); // HelloWorld
toCamelCase('hello_world'); // helloWorld```
# 5.# 删除数组中的重复值
```javascript
const removeDuplicates = (arr) => [...new Set(arr)]
console.log(removeDuplicates([1, 2, 2, 3, 3, 4, 4, 5, 5, 6]))
// [1, 2, 3, 4, 5, 6]
const flat = (arr) =>
[].concat.apply(
[],
arr.map((a) => (Array.isArray(a) ? flat(a) : a))
)
// Or
const flat = (arr) => arr.reduce((a, b) => (Array.isArray(b) ? [...a, ...flat(b)] : [...a, b]), [])
flat(['cat', ['lion', 'tiger']]) // ['cat', 'lion', 'tiger']
const removeFalsy = (arr) => arr.filter(Boolean)
removeFalsy([0, 'a string', '', NaN, true, 5, undefined, 'another string', false])
// ['a string', true, 5, 'another string']
const isEven = num => num % 2 === 0
isEven(2) // true
isEven(1) // false
const random = (min, max) => Math.floor(Math.random() * (max - min + 1) + min)
random(1, 50) // 25
random(1, 50) // 34
const average = (...args) => args.reduce((a, b) => a + b) / args.length;
average(1, 2, 3, 4, 5); // 3
const round = (n, d) => Number(Math.round(n + "e" + d) + "e-" + d)
round(1.005, 2) //1.01
round(1.555, 2) //1.56
const diffDays = (date, otherDate) => Math.ceil(Math.abs(date - otherDate) / (1000 * 60 * 60 * 24));
diffDays(new Date("2021-11-3"), new Date("2022-2-1")) // 90
const randomColor = () => `#${Math.random().toString(16).slice(2, 8).padEnd(6, '0')}`
randomColor() // #9dae4f
randomColor() // #6ef10e
const rgbToHex = (r, g, b) => "#" + ((1 << 24) + (r << 16) + (g << 8) + b).toString(16).slice(1)
rgbToHex(255, 255, 255) // '#ffffff'
const clearCookies = () => document.cookie.split(';').forEach((c) => (document.cookie = c.replace(/^ +/, '').replace(/=.*/, `=;expires=${new Date().toUTCString()};path=/`)))
const isDarkMode = window.matchMedia && window.matchMedia('(prefers-color-scheme: dark)').matches
[foo, bar] = [bar, foo]
const pause = (millis) => new Promise(resolve => setTimeout(resolve, millis))
const fn = async () => {
await pause(1000)
console.log('fatfish') // 1s later
}
fn()