The ?? operator in PHP is called the Null Coalescing Operator. It provides a simple way to handle null or undefined values, helping to prevent errors and making your code cleaner.
🛠 Syntax of the Null Coalescing Operator
The operator checks if a variable is set and not null. If it’s null, it returns a default value.
$variable = $_GET['name'] ?? 'Guest';
This means: “If $_GET['name'] is set, use it; otherwise, use 'Guest'.”
📝 Example 1: Handling Undefined Variables
Let’s safely access a variable that may not be set.
<?php
$name = $_GET['name'] ?? 'Guest';
echo "Hello, " . $name;
?>
📝 Example 2: Using Multiple Null Coalescing Operators
You can chain multiple values to find the first non-null value.
<?php
$username = $_POST['username'] ?? $_GET['username'] ?? 'Anonymous';
echo "User: " . $username;
?>
📝 Example 3: Using Null Coalescing in Arrays
Check if an array key exists before using it.
<?php
$data = ['name' => 'Alice'];
$user = $data['name'] ?? 'Unknown';
echo $user; // Output: Alice
?>
🎯 Why Use the Null Coalescing Operator?
- ✅ Prevents
undefined variableerrors - ✅ Makes code cleaner and shorter
- ✅ Great for handling form inputs and GET/POST requests
📝 Practice Time!
Try modifying the examples above and see how the null coalescing operator works with different values. The best way to learn is by experimenting! 🚀