Destruction of PHP session variables
1. What is session?
is equivalent to an access to the server by a client (which can be a browser, app, ftp, etc., and opening several more of the same browser can be considered different clients) , during this period the server creates a unique identifier (session_id session_name) for this purpose. session is actually an array Array(). The start and end of Session are not based on business input. It starts with the username and password and does not end with closing the browser and refreshing the webpagesession
2. Destruction of session variables
<?php session_unset(); session_destroy(); ?>
session_unset() //释放当前在内存中已经创建的所有$_SESSION变量,但不删除session文件以及不释放对应的session id
session_destroy() //删除当前用户对应的session文件以及释放session id,内存中的$_SESSION变量内容依然保留
[Note]:
Delete session method:
1. unset ($_SESSION['xxx']) Delete a single session, unset($_SESSION ['xxx']) is used to unregister a registered session variable. Its function is the same as session_unregister(). session_unregister() is no longer used in PHP5 and can be relegated to obsolescence.
unset($_SESSION) // 此函数千万不可使用,它会将全局变量$_SESSION销毁,而且还没有可行的办法将其恢复。用户也不再可以注册$_session变量。
2. $_SESSION=array() Delete multiple sessions
3. session_destroy() ends the current session and clears all resources in the session. . This function will not unset (release) global variables related to the current session, nor will it delete the client's session cookie. PHP's default session is based on cookies. If you want to delete cookies, you must use the setcookie() function.
Return value: Boolean value.
Function description: This function ends the current session. This function has no parameters, and the return value is true
Session_unset() If $_session is used, then this function The function no longer works. Since PHP5 must use $_session, this function can be relegated to the sidelines.
It can be concluded that steps to delete session:
①session_start()
②$_SESSION=array()/unset ($_session['xxx'])
③session_destroy()
Related recommendations:
Correctly log out of PHP SESSION, log out of phpsession_PHP tutorial
php uses session to prevent repeated page refreshes, phpsession prevents page_PHP tutorial
php passed Session anti-url attack method, phpsession anti-url_PHP tutorial
The above is the detailed content of Destruction of PHP session variables. For more information, please follow other related articles on the PHP Chinese website!

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

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Hot Topics











PHP and Python each have their own advantages, and choose according to project requirements. 1.PHP is suitable for web development, especially for rapid development and maintenance of websites. 2. Python is suitable for data science, machine learning and artificial intelligence, with concise syntax and suitable for beginners.

PHP is widely used in e-commerce, content management systems and API development. 1) E-commerce: used for shopping cart function and payment processing. 2) Content management system: used for dynamic content generation and user management. 3) API development: used for RESTful API development and API security. Through performance optimization and best practices, the efficiency and maintainability of PHP applications are improved.

PHP is a scripting language widely used on the server side, especially suitable for web development. 1.PHP can embed HTML, process HTTP requests and responses, and supports a variety of databases. 2.PHP is used to generate dynamic web content, process form data, access databases, etc., with strong community support and open source resources. 3. PHP is an interpreted language, and the execution process includes lexical analysis, grammatical analysis, compilation and execution. 4.PHP can be combined with MySQL for advanced applications such as user registration systems. 5. When debugging PHP, you can use functions such as error_reporting() and var_dump(). 6. Optimize PHP code to use caching mechanisms, optimize database queries and use built-in functions. 7

PHP is still dynamic and still occupies an important position in the field of modern programming. 1) PHP's simplicity and powerful community support make it widely used in web development; 2) Its flexibility and stability make it outstanding in handling web forms, database operations and file processing; 3) PHP is constantly evolving and optimizing, suitable for beginners and experienced developers.

PHP and Python each have their own advantages, and the choice should be based on project requirements. 1.PHP is suitable for web development, with simple syntax and high execution efficiency. 2. Python is suitable for data science and machine learning, with concise syntax and rich libraries.

PHP and Python have their own advantages and disadvantages, and the choice depends on project needs and personal preferences. 1.PHP is suitable for rapid development and maintenance of large-scale web applications. 2. Python dominates the field of data science and machine learning.

PHP is suitable for web development, especially in rapid development and processing dynamic content, but is not good at data science and enterprise-level applications. Compared with Python, PHP has more advantages in web development, but is not as good as Python in the field of data science; compared with Java, PHP performs worse in enterprise-level applications, but is more flexible in web development; compared with JavaScript, PHP is more concise in back-end development, but is not as good as JavaScript in front-end development.

PHP is mainly procedural programming, but also supports object-oriented programming (OOP); Python supports a variety of paradigms, including OOP, functional and procedural programming. PHP is suitable for web development, and Python is suitable for a variety of applications such as data analysis and machine learning.
