How to create and use sessions using PHP
Sessions are used in PHP to store and retrieve user data across requests. After a session is created, data can be stored and retrieved using the $_SESSION array. It is suitable for shopping cart management, user experience customization and login status maintenance. Create session code: session_start(); store data: $_SESSION['key'] = 'value'; retrieve data: $value = $_SESSION['key']; destroy session: session_destroy().
How to create and use sessions using PHP
Understanding sessions
Using sessions Used to store and retrieve user data across multiple user requests. This is useful for performing tasks such as tracking shopping cart contents, customizing the user experience, and maintaining login status.
Create session
To create a session, you can use the following code:
<?php session_start(); ?>
session_start() The function starts a session, If it doesn't exist yet, create it.
Storing session data
To store data, you can use the $_SESSION array:
<?php session_start(); // 存储用户名 $_SESSION['username'] = 'John Doe'; // 存储购物车内容 $_SESSION['cart'] = ['Apple', 'Orange', 'Banana']; ?>
Retrieve session data
To retrieve session data, you can access $_SESSION Array:
<?php session_start(); // 获取用户名 $username = $_SESSION['username']; // 获取购物车内容 $cart = $_SESSION['cart']; ?>
Case: Shopping Cart Management
Let's create a simple shopping cart management script to demonstrate how to use sessions:
cart.php
<?php
session_start();
// 添加产品
if (isset($_POST['add'])) {
$product = $_POST['product'];
$_SESSION['cart'][] = $product;
}
// 获取购物车内容
$cart = $_SESSION['cart'];
?>
<!DOCTYPE html>
<html>
<body>
<h1>购物车</h1>
<ul>
<?php
foreach ($cart as $item) {
echo "<li>" . $item . "</li>";
}
?>
</ul>
<form method="post">
<input type="text" name="product" placeholder="产品名称">
<input type="submit" name="add" value="添加">
</form>
</body>
</html>Use case:
- Open shopping cart.php and enter the product name in the form.
- Click the "Add" button to add the product to your shopping cart.
- Refresh the page to see the updated shopping cart contents.
Destroy the session
When the session is no longer needed, you can use the session_destroy() function to destroy it:
<?php session_start(); // 销毁会话 session_destroy(); ?>
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