Backend Development
PHP Tutorial
What are the differences between $_GET, $_POST, and $_REQUEST superglobals, and when should each be used?
What are the differences between $_GET, $_POST, and $_REQUEST superglobals, and when should each be used?
Jun 11, 2025 am 12:13 AM
In PHP, $_GET, $_POST, and $_REQUEST are used to collect data from HTTP requests, but for different purposes. 1. $_GET is used to retrieve non-sensitive data through URL query strings, suitable for scenarios such as filtering content, paging links, etc.; 2. $_POST is used to process sensitive or large amounts of data submitted through HTML forms, such as login information and file uploads; 3. $_REQUEST is a collection of $_GET, $_POST and $_COOKIE, providing a unified access method, but may cause conflicts. It is recommended to use $_GET or $_POST first to avoid ambiguity and security risks.
In PHP, $_GET , $_POST , and $_REQUEST are superglobals used to collect data from HTTP requests. While they all serve a similar purpose—retrieving user input—they different in how they access that data and when you should use them.
When to Use $_GET
$_GET is used to retrieve data sent via the URL query string. This means any form data or parameters approved to the URL after a question mark ( ? ) will be accessible through this superglobal.
It's most commonly used for non-sensitive data because the values ??are visible in the browser's address bar. For example:
// Example URL: http://example.com/page.php?name=John&age=30 echo $_GET['name']; // Outputs: John echo $_GET['age']; // Outputs: 30
Here are some common use cases:
- Filtering or sorting content (like search results)
- Pagination links
- Tracking referral sources
Just keep in mind:
- Data can be bookmarked or cached
- There's a limit to how much data you can send
- It's not secure for sensitive information
How and When to Use $_POST
$_POST is used to retrieve data submitted through an HTTP POST request, usually from an HTML form with method="post" . Unlike $_GET , this data doesn't show up in the URL, making it more suitable for sensitive or large amounts of information.
For example:
// HTML form // <form method="post" action="process.php"> // <input type="text" name="username"> // <input type="password" name="password"> // <button type="submit">Login</button> // </form> // In process.php $username = $_POST['username']; $password = $_POST['password'];
Use $_POST when:
- Handling login forms or payment details
- Uploading files
- Submitting large chunks of text (like blog posts)
Some advantages include:
- Better security (not exposed in URLs)
- No length limitations
- Can't be easily re-triggered by refreshing the page
Understanding $_REQUEST and Its Role
$_REQUEST is a catch-all variable that combines inputs from $_GET , $_POST , and even $_COOKIE . It gives you a way to access submitted data without worrying about the request method.
But here's the catch: since it merges multiple sources, there's a potential for conflicts or unexpected behavior if two inputs have the same name but come from different methods.
You might see something like this:
if ($_REQUEST['action'] === 'save') {
// Handle saving logic regardless of GET or POST
} While convenient, it's generally better to specify $_GET or $_POST depending on your needs. That way, you avoid ambiguity and reduce the risk of bugs or security issues.
Final Thoughts
Each of these superglobals has its place:
- Use
$_GETfor simple, non-sensitive data passed in URLs - Go with
$_POSTfor forms and secure subscriptions - Avoid overusing
$_REQUESTunless you really need flexibility
They're straightforward once you understand their strengths and limitations.
The above is the detailed content of What are the differences between $_GET, $_POST, and $_REQUEST superglobals, and when should each be used?. For more information, please follow other related articles on the PHP Chinese website!
Hot AI Tools
Undress AI Tool
Undress images for free
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
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
How to use PHP to build social sharing functions PHP sharing interface integration practice
Jul 25, 2025 pm 08:51 PM
The core method of building social sharing functions in PHP is to dynamically generate sharing links that meet the requirements of each platform. 1. First get the current page or specified URL and article information; 2. Use urlencode to encode the parameters; 3. Splice and generate sharing links according to the protocols of each platform; 4. Display links on the front end for users to click and share; 5. Dynamically generate OG tags on the page to optimize sharing content display; 6. Be sure to escape user input to prevent XSS attacks. This method does not require complex authentication, has low maintenance costs, and is suitable for most content sharing needs.
How to use PHP combined with AI to achieve text error correction PHP syntax detection and optimization
Jul 25, 2025 pm 08:57 PM
To realize text error correction and syntax optimization with AI, you need to follow the following steps: 1. Select a suitable AI model or API, such as Baidu, Tencent API or open source NLP library; 2. Call the API through PHP's curl or Guzzle and process the return results; 3. Display error correction information in the application and allow users to choose whether to adopt it; 4. Use php-l and PHP_CodeSniffer for syntax detection and code optimization; 5. Continuously collect feedback and update the model or rules to improve the effect. When choosing AIAPI, focus on evaluating accuracy, response speed, price and support for PHP. Code optimization should follow PSR specifications, use cache reasonably, avoid circular queries, review code regularly, and use X
PHP calls AI intelligent voice assistant PHP voice interaction system construction
Jul 25, 2025 pm 08:45 PM
User voice input is captured and sent to the PHP backend through the MediaRecorder API of the front-end JavaScript; 2. PHP saves the audio as a temporary file and calls STTAPI (such as Google or Baidu voice recognition) to convert it into text; 3. PHP sends the text to an AI service (such as OpenAIGPT) to obtain intelligent reply; 4. PHP then calls TTSAPI (such as Baidu or Google voice synthesis) to convert the reply to a voice file; 5. PHP streams the voice file back to the front-end to play, completing interaction. The entire process is dominated by PHP to ensure seamless connection between all links.
PHP creates a blog comment system to monetize PHP comment review and anti-brush strategy
Jul 25, 2025 pm 08:27 PM
1. Maximizing the commercial value of the comment system requires combining native advertising precise delivery, user paid value-added services (such as uploading pictures, top-up comments), influence incentive mechanism based on comment quality, and compliance anonymous data insight monetization; 2. The audit strategy should adopt a combination of pre-audit dynamic keyword filtering and user reporting mechanisms, supplemented by comment quality rating to achieve content hierarchical exposure; 3. Anti-brushing requires the construction of multi-layer defense: reCAPTCHAv3 sensorless verification, Honeypot honeypot field recognition robot, IP and timestamp frequency limit prevents watering, and content pattern recognition marks suspicious comments, and continuously iterate to deal with attacks.
PHP realizes commodity inventory management and monetization PHP inventory synchronization and alarm mechanism
Jul 25, 2025 pm 08:30 PM
PHP ensures inventory deduction atomicity through database transactions and FORUPDATE row locks to prevent high concurrent overselling; 2. Multi-platform inventory consistency depends on centralized management and event-driven synchronization, combining API/Webhook notifications and message queues to ensure reliable data transmission; 3. The alarm mechanism should set low inventory, zero/negative inventory, unsalable sales, replenishment cycles and abnormal fluctuations strategies in different scenarios, and select DingTalk, SMS or Email Responsible Persons according to the urgency, and the alarm information must be complete and clear to achieve business adaptation and rapid response.
How to use PHP to combine AI to generate image. PHP automatically generates art works
Jul 25, 2025 pm 07:21 PM
PHP does not directly perform AI image processing, but integrates through APIs, because it is good at web development rather than computing-intensive tasks. API integration can achieve professional division of labor, reduce costs, and improve efficiency; 2. Integrating key technologies include using Guzzle or cURL to send HTTP requests, JSON data encoding and decoding, API key security authentication, asynchronous queue processing time-consuming tasks, robust error handling and retry mechanism, image storage and display; 3. Common challenges include API cost out of control, uncontrollable generation results, poor user experience, security risks and difficult data management. The response strategies are setting user quotas and caches, providing propt guidance and multi-picture selection, asynchronous notifications and progress prompts, key environment variable storage and content audit, and cloud storage.
Beyond the LAMP Stack: PHP's Role in Modern Enterprise Architecture
Jul 27, 2025 am 04:31 AM
PHPisstillrelevantinmodernenterpriseenvironments.1.ModernPHP(7.xand8.x)offersperformancegains,stricttyping,JITcompilation,andmodernsyntax,makingitsuitableforlarge-scaleapplications.2.PHPintegrateseffectivelyinhybridarchitectures,servingasanAPIgateway
PHP integrated AI speech recognition and translator PHP meeting record automatic generation solution
Jul 25, 2025 pm 07:06 PM
Select the appropriate AI voice recognition service and integrate PHPSDK; 2. Use PHP to call ffmpeg to convert recordings into API-required formats (such as wav); 3. Upload files to cloud storage and call API asynchronous recognition; 4. Analyze JSON results and organize text using NLP technology; 5. Generate Word or Markdown documents to complete the automation of meeting records. The entire process needs to ensure data encryption, access control and compliance to ensure privacy and security.
