Detailed explanation of the tool function example of util in Vue

// Anti-shake functionfunction debounce (fn, wait) {
let t
return () => {
let context = this
let args = arguments
if (t) clearTimeout(t)
t = setTimeout(() => {
 (context, args)
}, wait)
}
}
function flatten (arr) { // Array flatteningreturn ((result, item) => {
return ((item) ? flatten(item) : item)
}, [])
}
function handleMulitePerson (sPerson) {
(44, (','))
if (typeof sPerson == 'string') {
let personArr = []
(',').forEach(item => {
 let obj = { userCode: ('/')[0], userName: ('/')[1] }
 (obj)
})
return personArr
}
}
function uniqueArray (array, key) { // json array is re-registered according to keyvar result = [array[0]]
for (var i = 1; i < ; i++) {
var item = array[i]
var repeat = false
for (var j = 0; j < ; j++) {
 if (item[key] == result[j][key]) {
  repeat = true
  break
 }
}
if (!repeat) {
 (item)
}
}
return result
}
function setSessionStorage (key, val) {
if (typeof (val) == 'object') {
(key, (val))
} else {
(key, val)
}
}
function getSessionStorage (key) {
return (key)
}
function removeStorage (key) {
(key)
}
function urlParams () { // Get link parametersvar str =  > 0 ? (1) : ''
var items =  ? ('&') : []
var args = {}
var item = null
var name = null
var value = null
for (let i = 0, len = ; i < len; i++) {
item = items[i].split('=')
name = decodeURIComponent(item[0])
value = decodeURIComponent(item[1])
if () {
 args[name] = value
}
};
return args
}
function urlAfterParams () {
var str =  > 0 ? (('?') + 1) : ''
var items = ('&') > 0 ? ('&') : ('?')
var args = {}
var item = null
var name = null
var value = null
for (let i = 0, len = ; i < len; i++) {
item = items[i].split('=')
name = decodeURIComponent(item[0])
value = decodeURIComponent(item[1])
if () {
 args[name] = value
}
};
return args
}
function parseParams (url) {
url = decodeURIComponent(url)
var params = {}
var idx = ('?')
if (idx > 0) {
var queryStr = (idx + 1)
if ( > 0) {
 var arr = ('&')
 for (let i = 0; i < ; i++) {
  var pair = arr[i].split('=')
  if ( == 2 && pair[0].length > 0) {
   params[pair[0]] = pair[1]
  }
 }
}
}
return params
}
/**
 Select person drop-down box data: username(userCode)
 */
function getSelectUserName (userName, userCode) {
return userName + '(' + userCode + ')'
}
function getSelectLoginUser () {
var userInfo = getLoginUserInfo()
return getSelectUserName(, )
}
function getUserNameBySelectUserName (userName) {
let i = ('(')
return (0, i)
}
/**
 Login user information
 userId
 userName
 mobileNo
 @returns {any}
 */
function getLoginUserInfo () {
return (('userInfo'))
}
function getLoginUserCode () {
return (('userInfo')).userId
}
export default {
getNyr,
getYDate,
setSessionStorage,
urlParams,
urlAfterParams,
parseParams,
debounce,
handleMulitePerson,
uniqueArray,
flatten,
getSessionStorage,
removeStorage,
getSelectUserName,
getSelectLoginUser,
getLoginUserInfo,
getLoginUserCode,
getUserNameBySelectUserName
}