PHP Super Globals - $_GET, $_POST, and $_REQUEST


Super globals in PHP are built-in global arrays that provide access to various forms of data, including user input, server information, and session data. In this guide, we'll provide an in-depth overview of three essential super globals in PHP: 

$_GET
, 
$_POST
, and 
$_REQUEST
. Understanding these super globals is crucial for handling data and building web applications.


1. Introduction to Super Globals

Let's start by understanding the concept of super globals in PHP and why they are crucial for web development.


2. The $_GET Super Global

The 

$_GET
super global is used to retrieve data sent to the server via URL parameters. It is often used for reading data from the URL.

http://example.com/index.php?name=John&age=30
$name = $_GET["name"];
$age = $_GET["age"];

3. The $_POST Super Global

The 

$_POST
super global is used to retrieve data sent to the server via HTTP POST requests, typically from HTML forms.

        
$username = $_POST["username"];
$password = $_POST["password"];

4. The $_REQUEST Super Global

The 

$_REQUEST
super global is a combination of 
$_GET
and 
$_POST
, making it useful for handling data from both URL parameters and form submissions.

$name = $_REQUEST["name"];
$email = $_REQUEST["email"];

5. Using Super Globals Securely

When working with super globals, it's essential to validate and sanitize user input to prevent security vulnerabilities like SQL injection and cross-site scripting (XSS).

$username = filter_input(INPUT_POST, "username", FILTER_SANITIZE_STRING);
$email = filter_input(INPUT_GET, "email", FILTER_VALIDATE_EMAIL);

6. Conclusion

You've now gained an in-depth understanding of PHP super globals, including 

$_GET
, 
$_POST
, and 
$_REQUEST
. Super globals are essential for handling data in web applications and should be used securely to protect against security risks.


To become proficient in working with super globals, practice, experiment, and apply your knowledge to real PHP projects.