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How to create and manage sessions using PHP built-in functions?

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Apr 22, 2024 am 11:18 AM

phpsession

The steps to manage sessions in PHP are as follows: Create a session: Use the session_start() function. Set session variables: Use the $_SESSION array to store data. Access session variables: Use the $_SESSION array to retrieve data from the session. Destroy the session: Use the session_destroy() function to end the session. Practical case: Login page: Verify login information and set session variables upon successful login. Home page: Check session variables and redirect to login page if user is not logged in. Exit page: Destroy the session and redirect to the login page.

如何使用 PHP 内置函数创建和管理会话？

How to create and manage sessions using PHP built-in functions

Sessions are a mechanism in web development for storing and managing information about users and their activities. In PHP, you can use the built-in session functions to efficiently create and manage sessions.

Create session

To create a session, use the following code:

<?php
session_start();
?>

session_start() The function will start a session and assign a session ID to the current browser user.

Set session variables

You can store data in session variables that will be accessible for the duration of the session. To set a session variable, use the following syntax:

<?php
session_start();
$_SESSION['name'] = 'John Doe';
?>

Access session variable

To access a session variable, use the following syntax:

<?php
session_start();
echo $_SESSION['name']; // 输出 "John Doe"
?>

Destroy session

The session can be destroyed by calling the session_destroy() function:

<?php
session_start();
session_destroy();
?>

Actual case

Login page

<?php
session_start();

if (isset($_POST['username']) && isset($_POST['password'])) {
  // 验证登录信息
  if ($isValidLogin) {
    $_SESSION['username'] = $_POST['username'];
  }
}
?>

<!DOCTYPE html>
<html>
  <head>
    <title>登录页面</title>
  </head>
  <body>
    <form method="post">
      <label for="username">用户名:</label>
      <input type="text" name="username" required>
      <br>
      <label for="password">密码:</label>
      <input type="password" name="password" required>
      <br>
      <input type="submit" value="登录">
    </form>
  </body>
</html>

Homepage

<?php
session_start();

if (!isset($_SESSION['username'])) {
  header('Location: login.php');
  exit;
}
?>

<!DOCTYPE html>
<html>
  <head>
    <title>首页</title>
  </head>
  <body>
    <h1 id="欢迎-php-echo-SESSION-username">欢迎 <?php echo $_SESSION['username']; ?></h1>
    <a href="logout.php">退出</a>
  </body>
</html>

Exit page

<?php
session_start();
session_destroy();
header('Location: login.php');
?>

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