【H5】 本地存储sessionStorage与localStorage
Storage特点:
1.存储量限制 ( 5M )
2.客户端完成,不会请求服务器处理
3.sessionStorage数据是不共享、 localStorage共享
sessionStorage:
作用于当前的页面,新开页面或者关闭页面时候,数据消失;
localStorage:
当数据有修改或删除的情况下,就会触发storage事件
在对数据进行改变的窗口对象上是不会触发的
Key : 修改或删除的key值,如果调用clear(),key为null
newValue : 新设置的值,如果调用removeStorage(),key为null
oldValue : 调用改变前的value值
storageArea : 当前的storage对象
url : 触发该脚本变化的文档的url
注:session同窗口才可以,例子:iframe操作
sessionStorage方法:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
</head>
<body>
<button id='addData'> 添加数据 </button>
<button id='getData'> 获取数据 </button>
<button id='removeData'> 删除数据 </button>
<input type="text" id='txt'>
<script>
const addData = document.getElementById('addData')
const getData = document.getElementById('getData')
const removeData = document.getElementById('removeData')
const txt = document.getElementById('txt')
addData.onclick = function(){
sessionStorage.setItem( 'key',txt.value );
}
getData.onclick = function(){
let val = sessionStorage.getItem('key')
alert( val )
}
removeData.onclick = function(){
sessionStorage.removeItem('key' );
}
</script>
</body>
</html>
localStorage本地缓存:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
</head>
<body>
<button id='addData'> 添加数据 </button>
<button id='getData'> 获取数据 </button>
<button id='removeData'> 删除数据 </button>
<input type="text" id='txt'>
<script>
const addData = document.getElementById('addData')
const getData = document.getElementById('getData')
const removeData = document.getElementById('removeData')
const txt = document.getElementById('txt')
addData.onclick = function(){
localStorage.setItem( 'key',txt.value );
}
getData.onclick = function(){
let val = localStorage.getItem('key')
alert( val )
}
removeData.onclick = function(){
localStorage.removeItem('key' );
}
</script>
</body>
</html>