How session.invalidate Session works
Let's take a look at how Session works. I wonder if you know that identity authentication is achieved through cookies. First, a unique cookie is generated as a sign of user identity and registered in the database. The cookie passed by the user is then compared with the cookie registered in the database to determine the user's identity.
Session works the same way.
First, PHP generates a unique string for the user who created the session to identify the user's session. This string is generally called Session Id. Then "sess" + Session Id is the file name (for example, if a Session ID is 111, then the file name is sess_111), create a file in the server's file system, and save the variable names and values of the global variables defined by the user in the Session in the file. Then the Session Id is saved in the user's file system as a cookie named PHPSession.
Then, when the user connects to the server again to access a PHP script, PHP gets the Session Id of the session where the user is from the PEESession cookie sent by the user, and saves the session information file from the server's file system based on the Session Id. Finally, the value of the global variable set by the user during the last connection is read from this file.
Therefore, we can see that the working principle of Session is the same as the working principle of identity authentication introduced in the previous section. The only difference is that Session saves the information in the server's file system, and we save the information in the database. Of course, the advantage of using Session is that data saving and retrieval are automatically completed by PHP, but if you use Cookie directly, you need to save and obtain data yourself.
Session uses the identity mark function of Cookie to save the information that users need to save when browsing the website on the server. In this way, Session not only overcomes the shortcomings of the HTTP protocol, but also prevents information leakage, and is convenient for programmers to use. It is a very good solution. However, the Session function is only supported by PHP4, and PHP3 does not support Session. Therefore, readers who use PHP3 to build websites can only use cookies directly.
The above introduces the working method of session.invalidate Session, including the content of session.invalidate. I hope it will be helpful to friends who are interested in PHP tutorials.
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
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,
What are Enumerations (Enums) in PHP 8.1?
Apr 03, 2025 am 12:05 AM
The enumeration function in PHP8.1 enhances the clarity and type safety of the code by defining named constants. 1) Enumerations can be integers, strings or objects, improving code readability and type safety. 2) Enumeration is based on class and supports object-oriented features such as traversal and reflection. 3) Enumeration can be used for comparison and assignment to ensure type safety. 4) Enumeration supports adding methods to implement complex logic. 5) Strict type checking and error handling can avoid common errors. 6) Enumeration reduces magic value and improves maintainability, but pay attention to performance optimization.
How does session hijacking work and how can you mitigate it in PHP?
Apr 06, 2025 am 12:02 AM
Session hijacking can be achieved through the following steps: 1. Obtain the session ID, 2. Use the session ID, 3. Keep the session active. The methods to prevent session hijacking in PHP include: 1. Use the session_regenerate_id() function to regenerate the session ID, 2. Store session data through the database, 3. Ensure that all session data is transmitted through HTTPS.
Describe the SOLID principles and how they apply to PHP development.
Apr 03, 2025 am 12:04 AM
The application of SOLID principle in PHP development includes: 1. Single responsibility principle (SRP): Each class is responsible for only one function. 2. Open and close principle (OCP): Changes are achieved through extension rather than modification. 3. Lisch's Substitution Principle (LSP): Subclasses can replace base classes without affecting program accuracy. 4. Interface isolation principle (ISP): Use fine-grained interfaces to avoid dependencies and unused methods. 5. Dependency inversion principle (DIP): High and low-level modules rely on abstraction and are implemented through dependency injection.
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 is REST API design principles?
Apr 04, 2025 am 12:01 AM
RESTAPI design principles include resource definition, URI design, HTTP method usage, status code usage, version control, and HATEOAS. 1. Resources should be represented by nouns and maintained at a hierarchy. 2. HTTP methods should conform to their semantics, such as GET is used to obtain resources. 3. The status code should be used correctly, such as 404 means that the resource does not exist. 4. Version control can be implemented through URI or header. 5. HATEOAS boots client operations through links in response.
How do you handle exceptions effectively in PHP (try, catch, finally, throw)?
Apr 05, 2025 am 12:03 AM
In PHP, exception handling is achieved through the try, catch, finally, and throw keywords. 1) The try block surrounds the code that may throw exceptions; 2) The catch block handles exceptions; 3) Finally block ensures that the code is always executed; 4) throw is used to manually throw exceptions. These mechanisms help improve the robustness and maintainability of your code.
What are anonymous classes in PHP and when might you use them?
Apr 04, 2025 am 12:02 AM
The main function of anonymous classes in PHP is to create one-time objects. 1. Anonymous classes allow classes without names to be directly defined in the code, which is suitable for temporary requirements. 2. They can inherit classes or implement interfaces to increase flexibility. 3. Pay attention to performance and code readability when using it, and avoid repeatedly defining the same anonymous classes.
