localStorage H5本地存储

域内安全、永久保存。即客户端或浏览器中来自同一域名的所有页面都可访问localStorage数据且数据除了删除否则永久保存，但客户端或浏览器之间的数据相互独立。

<!doctype html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Document</title>
</head>
<body>
    
</body>
</html>
<script type="text/javascript">
    
    localStorage.setItem("coffeeType", "mocha");     //存储
    var data = localStorage.getItem("coffeeType");   //读取
    console.log(data);

    localStorage.removeItem("coffeeType");           //删除
    var data2 = localStorage.getItem("coffeeType");   //读取
    console.log(data2);

    localStorage.clear();      //清空保存的所有数据

    localStorage.setItem("haha", "123");     //存储

</script>

<!doctype html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Document</title>
</head>
<body>
    <button onclick="read();">读取</button>
</body>
</html>
<script type="text/javascript">
    
    

    function read(){
        var data = localStorage.getItem("haha");   //读取
        alert(data);
    }

    

</script>