手记

【适合收藏】让你减少加班的15条高效JS技巧!

鱼头辛苦总结的15条非常高效的JS技巧,掌握这15个JS技巧,让你减少加班次数,多抽出点时间来陪女(男)朋友。

正文

延迟函数delay


const  delay = ms  =>  new  Promise((resolve, reject) =>  setTimeout(resolve, ms))

  

const  getData = status  =>  new  Promise((resolve, reject) => {

status ? resolve('done') : reject('fail')

})

const  getRes = async (data) => {

try {

const  res = await  getData(data)

const  timestamp = new  Date().getTime()

await  delay(1000)

console.log(res, new  Date().getTime() - timestamp)

} catch (error) {

console.log(error)

}

}

getRes(true)

分割指定长度的元素数组


const  listChunk = (list, size = 1, cacheList = []) => {

const  tmp = [...list]

if (size <= 0) {

return  cacheList

}

while (tmp.length) {

cacheList.push(tmp.splice(0, size))

}

return  cacheList

}

  

console.log(listChunk([1, 2, 3, 4, 5, 6, 7, 8, 9])) // [[1], [2], [3], [4], [5], [6], [7], [8], [9]]

console.log(listChunk([1, 2, 3, 4, 5, 6, 7, 8, 9], 3)) // [[1, 2, 3], [4, 5, 6], [7, 8, 9]]

console.log(listChunk([1, 2, 3, 4, 5, 6, 7, 8, 9], 0)) // []

console.log(listChunk([1, 2, 3, 4, 5, 6, 7, 8, 9], -1)) // []

获取数组交集


const  intersection = (list, ...args) =>  list.filter(item  =>  args.every(list  =>  list.includes(item)))

  

console.log(intersection([2, 1], [2, 3])) // [2]

console.log(intersection([1, 2], [3, 4])) // []

函数柯里化


const  curring = fn  => {

const { length } = fn

const  curried = (...args) => {

return (args.length >= length

? fn(...args)

: (...args2) =>  curried(...args.concat(args2)))

}

return  curried

}

  

const  listMerge = (a, b, c) => [a, b, c]

const  curried = curring(listMerge)

console.log(curried(1)(2)(3)) // [1, 2, 3]

  

console.log(curried(1, 2)(3)) // [1, 2, 3]

  

console.log(curried(1, 2, 3)) // [1, 2, 3]

字符串前面空格去除与替换


const  trimStart = str  =>  str.replace(new  RegExp('^([\\s]*)(.*)$'), '$2')

console.log(trimStart(' abc ')) // abc

console.log(trimStart('123 ')) // 123

字符串后面空格去除与替换


const  trimEnd = str  =>  str.replace(new  RegExp('^(.*?)([\\s]*)$'), '$1')

console.log(trimEnd(' abc ')) // abc

console.log(trimEnd('123 ')) // 123

获取当前子元素是其父元素下子元素的排位


const  getIndex = el  => {

if (!el) {

return -1

}

let  index = 0

do {

index++

} while (el = el.previousElementSibling);

return  index

}

获取当前元素相对于document的偏移量


const  getOffset = el  => {

const {

top,

left

} = el.getBoundingClientRect()

const {

scrollTop,

scrollLeft

} = document.body

return {

top:  top + scrollTop,

left:  left + scrollLeft

}

}

获取元素类型


const  dataType = obj  =>  Object.prototype.toString.call(obj).replace(/^\[object (.+)\]$/, '$1').toLowerCase();

判断是否是移动端


const  isMobile = () =>  'ontouchstart'  in  window

fade动画


const  fade = (el, type = 'in') {

el.style.opacity = (type === 'in' ? 0 : 1)

let last = +new  Date()

const tick = () => {

const  opacityValue = (type === 'in'

? (new  Date() - last) / 400

: -(new  Date() - last) / 400)

el.style.opacity = +el.style.opacity + opacityValue

last = +new  Date()

if (type === 'in'

? (+el.style.opacity < 1)

: (+el.style.opacity > 0)) {

requestAnimationFrame(tick)

}

}

tick()

}

将指定格式的字符串解析为日期字符串


const  dataPattern = (str, format = '-') => {

if (!str) {

return  new  Date()

}

const  dateReg = new  RegExp(`^(\\d{2})${format}(\\d{2})${format}(\\d{4})$`)

const [, month, day, year] = dateReg.exec(str)

return  new  Date(`${month}, ${day}  ${year}`)

}

  

console.log(dataPattern('12-25-1995')) // Mon Dec 25 1995 00:00:00 GMT+0800 (中国标准时间)

禁止网页复制粘贴


const  html = document.querySelector('html')

html.oncopy = () =>  false

html.onpaste = () =>  false

input框限制只能输入中文


const  input = document.querySelector('input[type="text"]')

const  clearText = target  => {

const {

value

} = target

target.value = value.replace(/[^\u4e00-\u9fa5]/g, '')

}

input.onfocus = ({target}) => {

clearText(target)

}

input.onkeyup = ({target}) => {

clearText(target)

}

input.onblur = ({target}) => {

clearText(target)

}

input.oninput = ({target}) => {

clearText(target)

}

去除字符串中的html代码


const  removeHTML = (str = '') =>  str.replace(/<[\/\!]*[^<>]*>/ig, '')

console.log(removeHTML('<h1>哈哈哈哈<呵呵呵</h1>')) // 哈哈哈哈<呵呵呵

后记

以上15个技巧都是我在日常开发中经常用到的一些代码片段,善用这些技巧,可以大大减少我们的开发时间。如果此时正在看文章的你也有类似的技巧心得,不妨在下方留言来分享给大家。

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