PHP $_GET

In PHP, the $_GET superglobal is used to collect form data and retrieve values from the URL query string. It is commonly used in search forms, navigation links, and API requests.

🔹 How Does $_GET Work?

When a user visits a URL like:

https://example.com/page-get.php?name=John&age=25

PHP can access the values using $_GET like this:

in page-get.php

<?php
$name = $_GET['name']; // Retrieves "John"
$age = $_GET['age'];   // Retrieves "25"

echo "Hello, $name! You are $age years old.";
?>

Output: Hello, John! You are 25 years old.

🔹 Using $_GET with HTML Forms

When using a form with method="get", data is sent as a query string in the URL.

<form action="welcome.php" method="get">
    Name: <input type="text" name="name"> <br>
    Age: <input type="number" name="age"> <br>
    <input type="submit" value="Submit">
</form>

When the user submits the form, the URL changes to:

https://example.com/welcome.php?name=Alice&age=30

Then, in welcome.php:

<?php
if (isset($_GET['name']) && isset($_GET['age'])) {
    echo "Welcome, " . $_GET['name'] . "! You are " . $_GET['age'] . " years old.";
} else {
    echo "Please enter your details.";
}
?>

🔹 Handling Missing or Undefined $_GET Variables

Always check if the key exists using isset() to avoid errors.

<?php
$name = isset($_GET['name']) ? $_GET['name'] : "Guest";
echo "Hello, $name!";
?>

Output: If no name is provided in the URL, it defaults to “Guest”.

🔹 Security Concerns with $_GET

• 🚨 Never use `$_GET` to send sensitive data (like passwords) since it’s visible in the URL.
• 🛡 Always sanitize input to prevent XSS (Cross-Site Scripting) and SQL injection.

Use htmlspecialchars() to prevent malicious input:

<?php
$name = isset($_GET['name']) ? htmlspecialchars($_GET['name']) : "Guest";
echo "Welcome, $name!";
?>

🎯 Key Takeaways

• $_GET retrieves values from the URL query string.
• Used in links, forms, and APIs to send data.
• Always check with isset() before using to prevent errors.
• Use htmlspecialchars() to prevent XSS attacks.

📝 Practice Time!

Modify the examples and create a **funny character generator** that accepts a name and favorite color via $_GET!