What Are Interfaces in PHP? | PHP Interface Example & Benefits
Category: Oop
Learn what interfaces are in PHP, how to use them with examples, and why they matter. Improve code consistency, scalability, and flexibility using PHP interfaces in OOP.
In PHP, an interface is a blueprint that defines method signatures without implementation. Classes use implements to follow the interface rules. Interfaces promote code consistency, scalability, and allow multiple implementations across unrelated classes.
✅ Key Features:
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Defined using the interface keyword
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Only method names and parameters—no logic
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Classes use implements to adopt an interface
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A class can implement multiple interfaces
🧠 Example:
interface PaymentGateway { public function charge($amount); } class PayPal implements PaymentGateway { public function charge($amount) { echo "Charging $$amount via PayPal."; } }
🎯 Why Use Interfaces in PHP?
| Benefit | Description |
|---|---|
| ✅ Code Consistency | Enforces same structure across classes |
| ✅ Scalability | Makes large codebases easier to manage |
| ✅ Dependency Injection | Works well in clean design patterns |
| ✅ Flexibility | Multiple classes can implement in their own way |
