How to use session in php: 1. Start PHP Session and place the [session_start()] function in front of the [] tag; 2. Use [PHP $_SESSION] to store Session variables; 3. Use [unset() 】Destroy Session.
How to use session in php:
Related topic recommendations:php session (including pictures, texts, videos, cases)
PHP Session variable
When you operate an application on your computer , you open it, make some changes, and then close it. It's a lot like a conversation. The computer knows who you are. It knows when you open and close apps. However, on the Internet a problem arises: since HTTP addresses cannot maintain state, the web server has no idea who you are and what you do.
PHP session solves this problem by storing user information on the server for subsequent use (such as user name, purchased items, etc.). However, session information is temporary and will be deleted after the user leaves the site. If you need to store information permanently, you can store the data in a database.
The working mechanism of Session is to create a unique id (UID) for each visitor and store variables based on this UID. The UID is stored in a cookie or passed through the URL.
Starting a PHP Session
Before you can store user information in a PHP session, you must first start the session.
Note: session_start()The function must be located before the tag:
Example
<?php session_start(); ?> <html> <body> </body> </html>
The above code The user's session is registered with the server so that you can start saving user information, and a UID is assigned to the user's session.
Storing Session Variables
The correct way to store and retrieve session variables is to use PHP $_SESSION Variables:
Example
<?php session_start(); // 存储 session 数据 $_SESSION['views']=1; ?> <html> <head> <meta charset="utf-8"> <title>菜鸟教程(runoob.com)</title> </head> <body> <?php // 检索 session 数据 echo "浏览量：". $_SESSION['views']; ?> </body> </html>
Output:
浏览量：1
In the following example, we create a simple page-view counter. isset()The function detects whether the "views" variable has been set. If the "views" variable is set, we increment the counter. If "views" does not exist, create the "views" variable and set it to 1:
Instance
<?php
session_start();
if(isset($_SESSION['views']))
{
$_SESSION['views']=$_SESSION['views']+1;
}
else
{
$_SESSION['views']=1;
}
echo "浏览量：". $_SESSION['views'];
?>Destroy Session
if If you want to delete some session data, you can use the unset() or session_destroy() function.
unset()The function is used to release the specified session variable:
Example
<?php
session_start();
if(isset($_SESSION['views']))
{
unset($_SESSION['views']);
}
?>You can also call session_destroy() Function to completely destroy the session:
Example
<?php session_destroy(); ?>
Related learning recommendations: PHP programming from entry to proficiency
The above is the detailed content of How to use session in php?. For more information, please follow other related articles on the PHP Chinese website!
ACID vs BASE Database: Differences and when to use each.Mar 26, 2025 pm 04:19 PMThe article compares ACID and BASE database models, detailing their characteristics and appropriate use cases. ACID prioritizes data integrity and consistency, suitable for financial and e-commerce applications, while BASE focuses on availability and
PHP Secure File Uploads: Preventing file-related vulnerabilities.Mar 26, 2025 pm 04:18 PMThe article discusses securing PHP file uploads to prevent vulnerabilities like code injection. It focuses on file type validation, secure storage, and error handling to enhance application security.
PHP Input Validation: Best practices.Mar 26, 2025 pm 04:17 PMArticle discusses best practices for PHP input validation to enhance security, focusing on techniques like using built-in functions, whitelist approach, and server-side validation.
PHP API Rate Limiting: Implementation strategies.Mar 26, 2025 pm 04:16 PMThe article discusses strategies for implementing API rate limiting in PHP, including algorithms like Token Bucket and Leaky Bucket, and using libraries like symfony/rate-limiter. It also covers monitoring, dynamically adjusting rate limits, and hand
PHP Password Hashing: password_hash and password_verify.Mar 26, 2025 pm 04:15 PMThe article discusses the benefits of using password_hash and password_verify in PHP for securing passwords. The main argument is that these functions enhance password protection through automatic salt generation, strong hashing algorithms, and secur
OWASP Top 10 PHP: Describe and mitigate common vulnerabilities.Mar 26, 2025 pm 04:13 PMThe article discusses OWASP Top 10 vulnerabilities in PHP and mitigation strategies. Key issues include injection, broken authentication, and XSS, with recommended tools for monitoring and securing PHP applications.
PHP XSS Prevention: How to protect against XSS.Mar 26, 2025 pm 04:12 PMThe article discusses strategies to prevent XSS attacks in PHP, focusing on input sanitization, output encoding, and using security-enhancing libraries and frameworks.
PHP Interface vs Abstract Class: When to use each.Mar 26, 2025 pm 04:11 PMThe article discusses the use of interfaces and abstract classes in PHP, focusing on when to use each. Interfaces define a contract without implementation, suitable for unrelated classes and multiple inheritance. Abstract classes provide common funct
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
AI Hentai Generator
Generate AI Hentai for free.
Hot Article
Hot Tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Safe Exam Browser
Safe Exam Browser is a secure browser environment for taking online exams securely. This software turns any computer into a secure workstation. It controls access to any utility and prevents students from using unauthorized resources.
MantisBT
Mantis is an easy-to-deploy web-based defect tracking tool designed to aid in product defect tracking. It requires PHP, MySQL and a web server. Check out our demo and hosting services.
SecLists
SecLists is the ultimate security tester's companion. It is a collection of various types of lists that are frequently used during security assessments, all in one place. SecLists helps make security testing more efficient and productive by conveniently providing all the lists a security tester might need. List types include usernames, passwords, URLs, fuzzing payloads, sensitive data patterns, web shells, and more. The tester can simply pull this repository onto a new test machine and he will have access to every type of list he needs.
ZendStudio 13.5.1 Mac
Powerful PHP integrated development environment
