Detailed tutorial on using PHP Cookie_PHP tutorial
1. Set Cookie
PHP uses the SetCookie function to set Cookie. One thing that must be noted is that cookies are part of the HTTP protocol header and are used to transfer information between the browser and the server, so the Cookie function must be called before any content belonging to the HTML file itself is output.
The SetCookie function defines a Cookie and appends it to the end of the HTTP header. The prototype of the SetCookie function is as follows:
int SetCookie(string name, string value, int expire, string path, string domain, int secure);
All parameters except name are optional. The three parameters value, path, and domain can be replaced with empty strings, indicating that they are not set; the expire and secure parameters are numerical and can be represented by 0. The expire parameter is a standard Unix time stamp, which can be obtained using the time() or mktime() function, in seconds. The
secure parameter indicates whether this cookie is transmitted over the network through the encrypted HTTPS protocol.
The currently set cookie does not take effect immediately, but will not be visible until the next page. This is because the cookie is passed from the server to the client's browser in the page that is set, and the browser will not see it until the next page. The reason why the cookie can be removed from the client's machine and sent back to the server.
Setting cookies on the same page is actually from back to front, so if you want to delete a cookie before inserting a new one, you must first write the insertion statement, and then write the deletion statement, otherwise there may be inaccuracies. desired results.
Let’s look at a few examples:
Simple:
SetCookie("MyCookie", "Value of MyCookie");
With expiration time:
SetCookie("WithExpire", "Expire in 1 hour", time()+3600);//3600 seconds=1 hour
Everything is available:
SetCookie("FullCookie", "Full cookie value", time()+3600, "/forum", ".phpuser.com", 1);
There is another point to note here. For example, your site has several different directories. So if you only use cookies without a path, the cookies set in a page in one directory will not be visible in a page in another directory. In other words, cookies are path-oriented. In fact, even if the path is not specified, the WEB server will automatically pass the current path to the browser, and specifying the path will force the server to use the set path. The way to solve this problem is to add the path and domain name when calling SetCookie. The format of the domain name can be "www.phpuser.com" or ". phpuser.com".
The part representing the value in the SetCookie function will be automatically encoded when passed. In other words, if the value of the value is "test value", it will become "test%20value" when passed, the same as the URL method. . Of course, this is transparent to the program, because PHP automatically decodes the cookie value when it receives it.
If you want to set multiple cookies with the same name, use an array. The method is:
SetCookie("CookieArray[]", "Value 1");
SetCookie("CookieArray[]", "Value 2");
or
SetCookie("CookieArray[0]", "Value 1");
SetCookie("CookieArray[1]", "Value 2");
2. Receiving and processing Cookies
PHP has very good support for receiving and processing Cookies. It is completely automatic, just like the principle of FORM variables, it is very simple.
For example, if you set a cookie named MyCookier, PHP will automatically analyze it from the HTTP header received by the WEB server and form a variable like an ordinary variable named $myCookie. The value of this variable is the cookie. value. The same applies to arrays. Another way is to reference PHP's global variable $HTTP_COOKIE_VARS array.
Examples are as follows: (assuming these have been set in previous pages and are still valid)
echo $MyCookie;
echo $CookieArray[0];
echo count($CookieArray) ;
echo $HTTP_COOKIE_VARS["MyCookie"];
It’s that simple.
3. Delete Cookie
To delete an existing cookie, there are two ways:
One is to call only with SetCookie of the name parameter, then the cookie named this name will be deleted from the related user computer;
Another way is to set the cookie expiration time to time() or time()-1, then the cookie will be on this page After browsing, it was deleted (actually it became invalid).
It should be noted that when a cookie is deleted, its value is still valid on the current page.
4. Restrictions on using cookies
First of all, it must be set before the content of the HTML file is output;
Secondly, different browsers have different restrictions on cookies. Handling inconsistent terms and sometimes erroneous results. For example: MS IE+SERVICE PACK 1 cannot correctly handle Cookies with domain name and path, Netscape Communicator 4.05 and MS IE 3.0 cannot correctly handle Cookies without path and time. As for MS IE 5, it seems that it cannot handle cookies with domain name, path and time. This is something I discovered while designing the pages of this site.
The third limitation is on the client side.
The maximum number of cookies that can be created by a browser is 30, and each cookie cannot exceed 4KB. The total number of cookies that can be set by each WEB site cannot exceed 20.

PHP is a server-side scripting language used for dynamic web development and server-side applications. 1.PHP is an interpreted language that does not require compilation and is suitable for rapid development. 2. PHP code is embedded in HTML, making it easy to develop web pages. 3. PHP processes server-side logic, generates HTML output, and supports user interaction and data processing. 4. PHP can interact with the database, process form submission, and execute server-side tasks.

PHP has shaped the network over the past few decades and will continue to play an important role in web development. 1) PHP originated in 1994 and has become the first choice for developers due to its ease of use and seamless integration with MySQL. 2) Its core functions include generating dynamic content and integrating with the database, allowing the website to be updated in real time and displayed in personalized manner. 3) The wide application and ecosystem of PHP have driven its long-term impact, but it also faces version updates and security challenges. 4) Performance improvements in recent years, such as the release of PHP7, enable it to compete with modern languages. 5) In the future, PHP needs to deal with new challenges such as containerization and microservices, but its flexibility and active community make it adaptable.

The core benefits of PHP include ease of learning, strong web development support, rich libraries and frameworks, high performance and scalability, cross-platform compatibility, and cost-effectiveness. 1) Easy to learn and use, suitable for beginners; 2) Good integration with web servers and supports multiple databases; 3) Have powerful frameworks such as Laravel; 4) High performance can be achieved through optimization; 5) Support multiple operating systems; 6) Open source to reduce development costs.

PHP is not dead. 1) The PHP community actively solves performance and security issues, and PHP7.x improves performance. 2) PHP is suitable for modern web development and is widely used in large websites. 3) PHP is easy to learn and the server performs well, but the type system is not as strict as static languages. 4) PHP is still important in the fields of content management and e-commerce, and the ecosystem continues to evolve. 5) Optimize performance through OPcache and APC, and use OOP and design patterns to improve code quality.

PHP and Python have their own advantages and disadvantages, and the choice depends on the project requirements. 1) PHP is suitable for web development, easy to learn, rich community resources, but the syntax is not modern enough, and performance and security need to be paid attention to. 2) Python is suitable for data science and machine learning, with concise syntax and easy to learn, but there are bottlenecks in execution speed and memory management.

PHP is used to build dynamic websites, and its core functions include: 1. Generate dynamic content and generate web pages in real time by connecting with the database; 2. Process user interaction and form submissions, verify inputs and respond to operations; 3. Manage sessions and user authentication to provide a personalized experience; 4. Optimize performance and follow best practices to improve website efficiency and security.

PHP uses MySQLi and PDO extensions to interact in database operations and server-side logic processing, and processes server-side logic through functions such as session management. 1) Use MySQLi or PDO to connect to the database and execute SQL queries. 2) Handle HTTP requests and user status through session management and other functions. 3) Use transactions to ensure the atomicity of database operations. 4) Prevent SQL injection, use exception handling and closing connections for debugging. 5) Optimize performance through indexing and cache, write highly readable code and perform error handling.

Using preprocessing statements and PDO in PHP can effectively prevent SQL injection attacks. 1) Use PDO to connect to the database and set the error mode. 2) Create preprocessing statements through the prepare method and pass data using placeholders and execute methods. 3) Process query results and ensure the security and performance of the code.


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

Atom editor mac version download
The most popular open source editor

MinGW - Minimalist GNU for Windows
This project is in the process of being migrated to osdn.net/projects/mingw, you can continue to follow us there. MinGW: A native Windows port of the GNU Compiler Collection (GCC), freely distributable import libraries and header files for building native Windows applications; includes extensions to the MSVC runtime to support C99 functionality. All MinGW software can run on 64-bit Windows platforms.

EditPlus Chinese cracked version
Small size, syntax highlighting, does not support code prompt function

Dreamweaver Mac version
Visual web development tools

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