项目中常用的js封装

Drake
2018-07-17
JavaScript
/**
 *判断undefined返回空字符串
 */
function formatundefined(str) {
  if (str == null || str == undefined || str == "undefined") {
    return ""
  }
  return str
}

/**
 * 防抖
 * @param fn 方法
 * @param delay 时间
 * @returns {(function(...[*]): void)|*}
 *
 * demo ===>  debounce(fn, 1000)
 */
export const debounce = (fn, delay) => {
  let timer

  return function (...args) {
    if (timer) {
      clearTimeout(timer)
    }
    timer = setTimeout(() => {
      fn.apply(this, args)
    }, delay)
  }
}

/**
 * 节流
 * @param fn  方法
 * @param delay  时间
 * @returns {(function(...[*]): void)|*}
 *
 * demo ===> throttle(fn,1000)
 */
export const throttle = (fn, delay) => {
  let last = 0 // 上次触发时间

  return (...args) => {
    const now = Date.now()

    if (now - last > delay) {
      last = now
      fn.apply(this, args)
    }
  }
}

/**
 * 深拷贝
 * @param obj
 * @param cache
 * @returns {Date|RegExp|any}
 *
 * demo ===>
 * let obj = { name: 'Jack', address: { x: 100, y: 200 } };
 * deepClone(obj)
 */
export const deepClone = (obj, cache = new WeakMap()) => {
  if (typeof obj !== "object") return obj // 普通类型，直接返回
  if (obj === null) return obj
  if (cache.get(obj)) return cache.get(obj) // 防止循环引用，程序进入死循环
  if (obj instanceof Date) return new Date(obj)
  if (obj instanceof RegExp) return new RegExp(obj)

  // 找到所属原型上的constructor，所属原型上的constructor指向当前对象的构造函数
  const cloneObj = new obj.constructor()

  cache.set(obj, cloneObj) // 缓存拷贝的对象，用于处理循环引用的情况
  for (const key in obj) {
    if (obj.hasOwnProperty(key)) {
      cloneObj[key] = deepClone(obj[key], cache) // 递归拷贝
    }
  }
  return cloneObj
}

/**
 * 冒泡排序
 * @param arr
 * @returns {*}
 *
 * demo ===>
 * bubbleSort([3,1,2,5,8,6])
 * bubbleSort(['b','c','a','e','d'])
 */
export const bubbleSort = (arr) => {
  const len = arr.length

  for (let i = 0; i < len - 1; i += 1) {
    // 从第一个元素开始，比较相邻的两个元素，前者大就交换位置
    for (let j = 0; j < len - 1 - i; j++) {
      if (arr[j] > arr[j + 1]) {
        const num = arr[j]

        arr[j] = arr[j + 1]
        arr[j + 1] = num
      }
    }
  }
  return arr
}

/**
 * 数组去重
 * @param arr
 * @returns {[]}
 *
 * demo ===>
 * resetArr([1,2,2,2,3,4,5,6])
 * resetArr(['b','b','c','a','e','d'])
 */
export const resetArr = (arr) => {
  const res = []

  arr.forEach((item) => {
    if (res.indexOf(item) === -1) {
      res.push(item)
    }
  })
  return res
}

/**
 * 获取URL参数
 * @param type URL类型 1:不加密  2:加密
 * @returns {{[p: string]: string}}
 *
 * demo ===>
 * https://www.google.com?id=123&age=30
 * urlSearchParams(1) // {id: "123",name: "30"}
 *
 * https://www.google.com?user=%E9%98%BF%E9%A3%9E&age=16
 * urlSearchParams(2) // {user: '阿飞', age: '16'}
 */
export const urlSearchParams = (type = 1) => {
  if (type === 1) {
    // 创建一个URLSearchParams实例
    const urlSearchParams = new URLSearchParams(window.location.search)

    // 把键值对列表转换为一个对象
    return Object.fromEntries(urlSearchParams.entries())
  }
  const res = {},
    url = window.location.href

  if (url.includes("?")) {
    const str = url.split("?")[1],
      arr = str.split("&")

    arr.forEach((item) => {
      const key = item.split("=")[0],
        val = item.split("=")[1]

      res[key] = decodeURIComponent(val) // 解码
    })
  }
  return res
}

/**
 * 判断字符串是以什么结尾
 * @param str   abc123
 * @param target  123
 * @returns {boolean}
 */
export const confirmEnding = (str, target) => {
  // 请把你的代码写在这里
  var start = str.length - target.length
  var arr = str.substr(start, target.length)
  if (arr === target) {
    return true
  }
  return false
}

/**
 * 随机数范围
 * @param min
 * @param max
 * @returns {null|number}
 */
export const random = (min, max) => {
  if (arguments.length === 1) {
    return Math.floor(min + Math.random() * (max + 1 - min))
  } else {
    return null
  }
}

/**
 * 四舍五入
 * @param n         数
 * @param decimals  小数点后第几位
 * @returns {number}
 */
export const round = (n, decimals = 0) => {
  return Number(`${Math.round(`${n}e${decimals}`)}e-${decimals}`)
}

/**
 * 通过key来获取html?后面的数据
 * */
function getUrlParam(key) {
  var url = decodeURI(location.search.replace(/^\?/, "")).split("&")
  var paramsObj = {}
  for (var i = 0, iLen = url.length; i < iLen; i++) {
    var param = url[i].split("=")
    paramsObj[param[0]] = param[1]
  }
  if (key) {
    return paramsObj[key] || ""
  }
  return paramsObj
}

/**
 * 判断数据类型
 */
var toString = Object.prototype.toString
function type(elem) {
  if (elem == null) {
    return elem + ""
  }
  return toString
    .call(elem)
    .replace(/[\[\]]/g, "")
    .split(" ")[1]
    .toLowerCase()
}

/**
 * 判断数组是否包含元素
 * @param arr
 * @param obj
 * @returns {Boolean}
 */
function contains(arr, obj) {
  var i = arr.length
  while (i--) {
    if (arr[i] == obj) {
      return true
    }
  }
  return false
}

/**
 * 移除数组里的元素
 * @param arr
 * @param obj
 * @returns {Array}
 */
function remove(arr, obj) {
  var i = arr.length
  var newarr = new Array()
  while (i--) {
    if (arr[i] != obj) {
      newarr.push(arr[i])
    }
  }
  return newarr
}

/**
 * 原生拖拽
 */
function dragEvent(drag, dbody) {
  window.getSelection
    ? window.getSelection().removeAllRanges()
    : document.selection.empty()
  drag.onmousedown = function (event) {
    var event = event || window.event
    var pageX =
      event.pageX || event.clientX + document.documentElement.scrollLeft
    var pageY =
      event.pageY || event.clientY + document.documentElement.scrollTop
    var bodyX = pageX - dbody.offsetLeft
    var bodyY = pageY - dbody.offsetTop
    window.getSelection
      ? window.getSelection().removeAllRanges()
      : document.selection.empty()
    document.onmousemove = function (event) {
      var event = event || window.event
      var pageX =
        event.pageX || event.clientX + document.documentElement.scrollLeft
      var pageY =
        event.pageY || event.clientY + document.documentElement.scrollTop
      dbody.style.left = pageX - bodyX + "px"
      dbody.style.top = pageY - bodyY + "px"
      window.getSelection
        ? window.getSelection().removeAllRanges()
        : document.selection.empty()
    }
  }
  document.onmouseup = function () {
    document.onmousemove = null
  }
}

/**
 * 往数组里面增加属性
 * @param array
 * @param dataType
 */
function addDataType(array, dataType) {
  for (var i in array) {
    array[i].type = dataType
  }
}

/**
 * 获取当前日期时间 格式"yyyy-MM-dd HH:MM:SS"
 */
function getNowFormatDate() {
  var date = new Date()
  var seperator1 = "-"
  var seperator2 = ":"
  var month = date.getMonth() + 1
  var strDate = date.getDate()
  if (month >= 1 && month <= 9) {
    month = "0" + month
  }
  if (strDate >= 0 && strDate <= 9) {
    strDate = "0" + strDate
  }

  var currentdata =
    date.getFullYear() +
    seperator1 +
    month +
    seperator1 +
    strDate +
    " " +
    date.getHours() +
    seperator2 +
    date.getMinutes() +
    seperator2 +
    date.getSeconds()

  return currentdata
}

/**
 * 获取当前日期前一个月时间 格式"yyyy-MM-dd HH:MM:SS"
 */
function getLastFormatDate() {
  var date = new Date()
  date.setMonth(date.getMonth() - 1)
  var seperator1 = "-"
  var seperator2 = ":"
  var year = date.getFullYear()
  var month = date.getMonth() + 1
  var strDate = date.getDate()
  var hours = date.getHours()
  var seconds = date.getSeconds()
  var minutes = date.getMinutes()
  if (month >= 1 && month <= 9) {
    month = "0" + month
  }
  if (strDate >= 0 && strDate <= 9) {
    strDate = "0" + strDate
  }

  if (hours >= 0 && hours <= 9) {
    hours = "0" + hours
  }
  if (seconds >= 0 && seconds <= 9) {
    seconds = "0" + seconds
  }
  if (minutes >= 0 && minutes <= 9) {
    minutes = "0" + minutes
  }

  var lastdata =
    year +
    seperator1 +
    month +
    seperator1 +
    strDate +
    " " +
    hours +
    seperator2 +
    minutes +
    seperator2 +
    seconds

  return lastdata
}

/**
 * 随机生产6位数的数字
 */
function getUUidNum() {
  var code = Math.floor(Math.random() * 900000) + 100000
  return code
}

/**
 * 获取当天日期，获取前n天的日期
 */
function getCurrentDate() {
  var d = new Date()
  var year = d.getFullYear()
  var mon = d.getMonth() + 1
  var day = d.getDate()
  s =
    year +
    "-" +
    (mon < 10 ? "0" + mon : mon) +
    "-" +
    (day < 10 ? "0" + day : day)
  return s
}

/**
 * 获取前n天的日期
 */
function getBeforeDate(n) {
  var n = n
  var d = new Date()
  var year = d.getFullYear()
  var mon = d.getMonth() + 1
  var day = d.getDate()
  if (day <= n) {
    if (mon > 1) {
      mon = mon - 1
    } else {
      year = year - 1
      mon = 12
    }
  }
  d.setDate(d.getDate() - n)
  year = d.getFullYear()
  mon = d.getMonth() + 1
  day = d.getDate()
  s =
    year +
    "-" +
    (mon < 10 ? "0" + mon : mon) +
    "-" +
    (day < 10 ? "0" + day : day)
  return s
}