Backend Development
PHP Tutorial
PHP session session processing function, session session_PHP tutorial
PHP session session processing function, session session_PHP tutorial
PHP session session processing function, session session
PHP Session variable
When you run an application, you open it, make changes, and then close it. It's a lot like a session. The computer knows who you are. It knows when you start the application and when it terminates it. But on the Internet, there's a problem: the server doesn't know who you are and what you do, and that's because HTTP addresses don't maintain state.
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.
Session works by creating a unique id (UID) for each visitor and storing variables based on this UID. The UID is stored in a cookie or passed through the URL.
1. Start conversation
Before saving information to the session, you must first open the session. PHP provides the session_start() function to start or continue a session. Definition:
1 bool session_start( void )
The call is as follows:
1 2 3 4 |
|
Note:
(1) The session_start() function must be located before the tag, that is, the function must be called before any output. Often when writing a program, an extra space or carriage return is accidentally entered. In this case, An error will be reported. Special attention should be paid to this. (I have been tricked)
(2) The session_start() function will return TRUE regardless of whether the session is successfully created, so using any exception handling will not work.
(3) You can also enable the configuration instruction session.auto_start so that you do not have to execute this function, but in this case, a session will be started or continued when each php page is executed.
2. Store or read session
The correct way to store and read session variables is to use PHP's S ESSION variable. SESSION variable. _SESSION is a global parameter provided by PHP and is specially used to store and read sessions. (Note that the key names of associative arrays are consistent with the naming rules of ordinary variables)
When storing a session, you can assign it directly.
$_SESSION['season'] = 'Autumn';
The above sets a session element with the key name "season" and its value is "autumn". When reading, it is just like calling a normal array element.
The following two code snippets show how to store and read a session element.
This is the session1.php file:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 |
|
This is the session2.php file:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 |
|
In session1.php, first use session_start() to create a session, then use array assignment to store the submitted seasonal data, and finally use the header() function to jump directly to the beginning. In the session2.php file, the session_start() function is also needed to continue a session and use the session array to call session information.
3. Destroy session
When the session is no longer used, it needs to be destroyed manually. Although PHP has the function of automatically destroying the session, this will make the program less efficient. You can use the unset() function or session_destroy() function.
1 2 3 |
|
Or:
1 2 3 |
|
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
1389
52
PHP 8.4 Installation and Upgrade guide for Ubuntu and Debian
Dec 24, 2024 pm 04:42 PM
PHP 8.4 brings several new features, security improvements, and performance improvements with healthy amounts of feature deprecations and removals. This guide explains how to install PHP 8.4 or upgrade to PHP 8.4 on Ubuntu, Debian, or their derivati
7 PHP Functions I Regret I Didn't Know Before
Nov 13, 2024 am 09:42 AM
If you are an experienced PHP developer, you might have the feeling that you’ve been there and done that already.You have developed a significant number of applications, debugged millions of lines of code, and tweaked a bunch of scripts to achieve op
How To Set Up Visual Studio Code (VS Code) for PHP Development
Dec 20, 2024 am 11:31 AM
Visual Studio Code, also known as VS Code, is a free source code editor — or integrated development environment (IDE) — available for all major operating systems. With a large collection of extensions for many programming languages, VS Code can be c
Explain JSON Web Tokens (JWT) and their use case in PHP APIs.
Apr 05, 2025 am 12:04 AM
JWT is an open standard based on JSON, used to securely transmit information between parties, mainly for identity authentication and information exchange. 1. JWT consists of three parts: Header, Payload and Signature. 2. The working principle of JWT includes three steps: generating JWT, verifying JWT and parsing Payload. 3. When using JWT for authentication in PHP, JWT can be generated and verified, and user role and permission information can be included in advanced usage. 4. Common errors include signature verification failure, token expiration, and payload oversized. Debugging skills include using debugging tools and logging. 5. Performance optimization and best practices include using appropriate signature algorithms, setting validity periods reasonably,
How do you parse and process HTML/XML in PHP?
Feb 07, 2025 am 11:57 AM
This tutorial demonstrates how to efficiently process XML documents using PHP. XML (eXtensible Markup Language) is a versatile text-based markup language designed for both human readability and machine parsing. It's commonly used for data storage an
PHP Program to Count Vowels in a String
Feb 07, 2025 pm 12:12 PM
A string is a sequence of characters, including letters, numbers, and symbols. This tutorial will learn how to calculate the number of vowels in a given string in PHP using different methods. The vowels in English are a, e, i, o, u, and they can be uppercase or lowercase. What is a vowel? Vowels are alphabetic characters that represent a specific pronunciation. There are five vowels in English, including uppercase and lowercase: a, e, i, o, u Example 1 Input: String = "Tutorialspoint" Output: 6 explain The vowels in the string "Tutorialspoint" are u, o, i, a, o, i. There are 6 yuan in total
Explain late static binding in PHP (static::).
Apr 03, 2025 am 12:04 AM
Static binding (static::) implements late static binding (LSB) in PHP, allowing calling classes to be referenced in static contexts rather than defining classes. 1) The parsing process is performed at runtime, 2) Look up the call class in the inheritance relationship, 3) It may bring performance overhead.
What are PHP magic methods (__construct, __destruct, __call, __get, __set, etc.) and provide use cases?
Apr 03, 2025 am 12:03 AM
What are the magic methods of PHP? PHP's magic methods include: 1.\_\_construct, used to initialize objects; 2.\_\_destruct, used to clean up resources; 3.\_\_call, handle non-existent method calls; 4.\_\_get, implement dynamic attribute access; 5.\_\_set, implement dynamic attribute settings. These methods are automatically called in certain situations, improving code flexibility and efficiency.
