JavaScript常用工具函数库汇总

/**
 * 对象或数组的深拷贝
 * @param {*} cloneObj 被克隆的对象
 * @param {*} targetObj 克隆的目标对象
 * @param {*} isOverride 若属性重复，是否覆盖被克隆对象的属性
 */
function deepClone(cloneObj, targetObj, isOverride = true) {
  const _toString = Object.prototype.toString
  if (_toString.call(cloneObj) !== '[object Array]' && _toString.call(cloneObj) !== '[object Object]') {
    return cloneObj
  }
  var cloneTarget = _toString.call(cloneObj) === '[object Array]' ? [] : {}
  for (let key in cloneObj) {
    if (Object.prototype.hasOwnProperty.call(cloneObj, key)) {
      if (_toString.call(cloneObj[key]) === '[object Array]' || _toString.call(cloneObj[key]) === '[object Object]') {
        cloneTarget[key] = deepClone(cloneObj[key])
      } else {
        cloneTarget[key] = cloneObj[key]
      }
    }
  }
  if (targetObj && (_toString.call(cloneObj) === _toString.call(targetObj))) {
    //这里要注意，克隆的目标对象也要deepClone下
    cloneTarget = isOverride
      ? Object.assign(cloneTarget, deepClone(targetObj))
      : Object.assign(deepClone(targetObj), cloneTarget)
  }
  return cloneTarget
}

//精准判断数据类型
function getVerifyDataTypes() {
  const types = ["String", "Number", "Boolean", "Null", "Undefined", "Function", "Object", "Array", "Date", "Error", "RegExp", "Symbol", "Map", "Set"]
  let Type = {}
  // 示例用法：Type.isString('javascript')
  for (let i = 0; i < types.length; i++) {
    Type[`is${types[i]}`] = obj => Object.prototype.toString.call(obj) === `[object ${types[i]}]`
  }
  // 判断字符串是否为json格式
  Type.isJsonStr = str => {
    if (typeof str == 'string') {
      try {
        let obj = JSON.parse(str);
        if (obj && typeof obj == 'object') {
          return true;
        }
        return false;
      } catch (e) {
        return false;
      }
    } else {
      return false;
    }
  }
  return Type
}

/**
 * 日期格式化
 * @param {*} date 日期对象
 * @param {*} beforeHyphen 年月日连字符
 * @param {*} afterHyphen 时分秒连字符
 */
function formatDate(date = new Date(), beforeHyphen = '-', afterHyphen = ':') {
  const formatNumber = n => {
    n = n.toString()
    return n[1] ? n : `0${n}`
  }
  const year = date.getFullYear()
  const month = date.getMonth() + 1
  const day = date.getDate()
  const hour = date.getHours()
  const minute = date.getMinutes()
  const second = date.getSeconds()
  const ymd = [year, month, day].map(formatNumber).join(beforeHyphen)
  const hms = [hour, minute, second].map(formatNumber).join(afterHyphen)
  return `${ymd} ${hms}`
}

/**
 * 把时间戳转换为剩余的天、时、分、秒，一般应用于倒计时场景中
 * @param {*} timestamp 时间戳
 */
function converTimestamp(timestamp) {
  const formatNumber = n => {
    n = n.toString()
    return n[1] ? n : `0${n}`
  }
  let day = Math.floor((timestamp / 1000 / 3600) / 24);
  let hour = Math.floor((timestamp / 1000 / 3600) % 24);
  let minute = Math.floor((timestamp / 1000 / 60) % 60);
  let second = Math.floor(timestamp / 1000 % 60);
  return {
   day: day,
   hour: formatNumber(hour),
   minute: formatNumber(minute),
   second: formatNumber(second)
  }
}

// 从数组中随机取出一项
function getRandomItemByArray(items) {
  return items[Math.floor(Math.random() * items.length)];
}

let data = [
  { parentId: 0, id: 1, value: 'xxx' },
  { parentId: 1, id: 3, value: 'xxx' },
  { parentId: 4, id: 6, value: 'xxx' },
  { parentId: 3, id: 5, value: 'xxx' },
  { parentId: 2, id: 4, value: 'xxx' },
  { parentId: 1, id: 2, value: 'xxx' },
]

// 转换为树形Array结构
function toTreeAry(arr, pId = 0) {
  return arr
    .filter(({ parentId }) => parentId === pId)
    .map(a => ({
      ...a,
      children: toTreeAry(arr.filter(({ parentId }) => parentId !== pId), a.id)
    }))
}

// 转换为树形Object结构
function toTreeObj(arr, pId = 0) {
  let res = {}
  arr.filter(({ parentId }) => parentId === pId)
    .forEach(a => {
      res[a.id] = {
        ...a,
        children: toTreeObj(arr.filter(({ parentId }) => parentId !== pId), a.id)
      }
    })
  return res
}

console.log(toTreeAry(data))
console.log(toTreeObj(data))

// 随机字符串
const randomStr = () => {
  return new Date().getTime() + '-' + Math.random().toString(36).substr(2)
}

// 过滤html标签
const filterHTMLTag = (str) => {
  str = str.replace(/<\/?[^>]*>/g, ''); //去除HTML Tag
  str = str.replace(/[|]*\n/, '') //去除行尾空格
  str = str.replace(/&npsp;/ig, ''); //去掉npsp
  return str;
}