省市区三级联动
<!DOCTYPE html>
< html lang = " en" >
< head>
< meta charset = " UTF-8" >
< title> Document</ title>
</ head>
< body>
< select name = " " id = " province" >
</ select>
< select name = " " id = " city" >
</ select>
< select name = " " id = " area" >
</ select>
< script src = " machine.js " > </ script>
< script src = " citys.js " > </ script>
< script>
let province = $ ( "#province" ) ;
let city = $ ( "#city" ) ;
let area = $ ( "#area" ) ;
citys. forEach ( item=> {
let option = document. createElement ( "option" ) ;
option. innerHTML = item. provinceName;
province. appendChild ( option)
} )
function updateCity ( index) {
var index = index || 0 ;
city. innerHTML = "" ;
citys[ index] . mallCityList. forEach ( item=> {
let option = document. createElement ( "option" ) ;
option. innerHTML = item. cityName;
city. appendChild ( option)
} )
}
function updateArea ( provinceIndex, cityIndex) {
area. innerHTML = "" ;
citys[ provinceIndex] . mallCityList[ cityIndex] . mallAreaList. forEach ( item=> {
let option = document. createElement ( "option" ) ;
option. innerHTML = item. areaName;
area. appendChild ( option)
} )
}
updateCity ( 0 )
updateArea ( 0 , 0 )
province. onchange = function ( ) {
updateCity ( this . selectedIndex)
updateArea ( this . selectedIndex, city. selectedIndex)
}
city. onchange = function ( ) {
updateArea ( province. selectedIndex, this . selectedIndex)
}
</ script>
</ body>
</ html>
本地存储
写cookie
js">
function setCookie ( key, value, expires) {
if ( typeof expires === "number" ) {
let date = new Date ( ) ;
date. setDate ( date. getDate ( ) + expires)
document. cookie = ` ${ key} = ${ value} ;expires= ${ date} ` ;
} else {
let d = new Date ( expires) ;
document. cookie = ` ${ key} = ${ value} ;expires= ${ d} ` ;
}
}
读cookie
js">function getCookie ( key) {
let cookie = document. cookie;
let arr = cookie. split ( "; " ) ;
let result = { }
arr. forEach ( item=> {
let key = item. split ( "=" ) [ 0 ] ;
let value = item. split ( "=" ) [ 1 ] ;
result[ key] = value;
} )
if ( key) {
return result[ key] ;
}
return result;
}
删cookie(把储存的到期时间设置成过去的某天)
js">function removeCookie ( key) {
let guoqu = new Date ( "1970-01-01 00:00:00" )
if ( key) {
document. cookie = ` ${ key} =beybey;expires= ${ guoqu} `
}
else {
let cookie = getCookie ( ) ;
for ( let i in cookie) {
document. cookie = ` ${ i} =beybey;expires= ${ guoqu} `
}
}
}
cookie的写读删封装
js">let cookie = {
set ( key, value, expires) {
if ( typeof expires === "number" ) {
let date = new Date ( ) ;
date. setDate ( date. getDate ( ) + expires)
document. cookie = ` ${ key} = ${ value} ;expires= ${ date} ` ;
} else {
let d = new Date ( expires) ;
document. cookie = ` ${ key} = ${ value} ;expires= ${ d} ` ;
}
} ,
get ( key) {
let arr = document. cookie. split ( "; " )
var result = { }
arr. forEach ( item => {
let key = item. split ( "=" ) [ 0 ] ;
let value = item. split ( "=" ) [ 1 ] ;
result[ key] = value;
} )
return key ? result[ key] : result;
} ,
remove ( key) {
if ( this . get ( key) ) {
document. cookie = key + "=18;expires=" + new Date ( '1999-09-09' ) ;
return true ;
} else {
return false ;
}
}
}
案例
省市区三级联动 天气预报接入省市区三级联动(接口yiketianqi.com) 30天内免登录页面 todulist持久化存储