sessionStorage

 1 <!DOCTYPE html>
 2 <html lang="en">
 3 <head>
 4     <meta charset="UTF-8">
 5     <title>登录</title>
 6     <style>
 7         .login {
 8             width: 300px;
 9             height: 300px;
10             border: 1px solid green;
11             margin: 0 auto;
12             text-align: center;
13             padding-top: 10px;
14         }
15     </style>
16 </head>
17 <body>
18     <form action="" class="login">
19         <label for="name">账号:</label><input type="text" value="" id="name"><br>
20         <label for="pwd">密码:</label><input type="password" value="" id="pwd"><br>
21         <input class="btn" type="button" value="登录" onclick="login()">
22     </form>
23 </body>
24 <script>
25     window.document.onkeyup = function (ev) {
26         if (ev.keyCode == 13) {
27             login()
28         }
29     }
30     function Emp(account, password, nickname) {
31         this.account = account;
32         this.password = password;
33         this.nickname = nickname
34     }
35     function login() {
36         var name = document.getElementById('name');
37         var pwd = document.getElementById('pwd');
38         if (name.value.length == 0) {
39             alert('账号不能为空');
40             name.focus()
41         } else if (pwd.value.length == 0) {
42             alert('密码不能为空');
43             document.querySelector('#pwd').focus()
44         } else {
45             var emp = new Emp(name, pwd, '文康');
46             sessionStorage.setItem('op', JSON.stringify(emp));
47             window.location.replace('main.html')
48         }
49     }
50 
51 </script>
52 </html>

 1 <!DOCTYPE html>
 2 <html lang="en">
 3 <head>
 4     <meta charset="UTF-8">
 5     <title>SQL审核系统</title>
 6 </head>
 7 <body>
 8     开发者:<span id="operator"></span>
 9     <br>
10     <button onclick="logout()">退出系统</button>
11 </body>
12 <script>
13     window.onload = function () {
14         let operatorString = sessionStorage.getItem('op');
15         if (operatorString != null) {
16             document.querySelector('#operator').innerText = JSON.parse(operatorString).nickname;
17         } else {
18             logout()
19         }
20     };
21     function logout() {
22         sessionStorage.clear();
23         window.location.replace('login.html')
24     }
25 </script>
26 </html>

main.html