js 开发小技巧

总结一些能够提高开发效率的JS技巧，这些技巧很实用，觉得挺好，整理一下。

生成随机UID

const genUid = () => {
  var length = 20
  var soupLength = genUid.soup_.length
  var id = []
  for (var i = 0; i < length; i++) {
    id[i] = genUid.soup_.charAt(Math.random() * soupLength)
  }
  return id.join('')
}
genUid.soup_ = '!#$%()*+,-./:;=?@[]^_`{|}~ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789'
genUid() // ;l`yCPc9A8IuK}?N6,%}

无loop生成指定长度的数组

const List = len => [...new Array(len).keys()]
const list = List(10) // [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

数组去重

const list = [1, 1, 2, 3, 6, 45, 8, 5, 4, 6, 5]
const uniqueList = [...new Set(list)] // [1, 2, 3, 6, 45, 8, 5, 4]

RGB色值生成16进制色值

const rgb2Hex = (r, g, b) => {
    r = Math.max(Math.min(Number(r), 100), 0) * 2.55
    g = Math.max(Math.min(Number(g), 100), 0) * 2.55
    b = Math.max(Math.min(Number(b), 100), 0) * 2.55
    r = ('0' + (Math.round(r) || 0).toString(16)).slice(-2)
    g = ('0' + (Math.round(g) || 0).toString(16)).slice(-2)
    b = ('0' + (Math.round(b) || 0).toString(16)).slice(-2)
    return '#' + r + g + b
}
rgb2Hex(100, 50, 0) // "#ff7f00"

判断是否为质数

const mathIsPrime = n => {
  if (n === 2 || n === 3) {
    return true
  }
  if (isNaN(n) || n <= 1 || n % 1 != 0 || n % 2 == 0 || n % 3 == 0) {
    return false;
  }
  for (let x = 6; x <= Math.sqrt(n) + 1; x += 6) {
    if (n % (x - 1) == 0 || n % (x + 1) == 0) {
      return false
    }
  }
  return true
}
mathIsPrime(0) // true

遍历类数组对象

const elements = document.querySelectorAll(selector);
[].prototype.forEach.call(elements, (el, idx, list) => {
    console.log(el) // 元素节点
})

判断对象类型

const type = data => Object.prototype.toString.call(data).replace(/^\[object (.+)\]$/, '$1').toLowerCase()
type({}) // object