Basics

PHP Interfaces

PHP interfaces define contracts, supporting multiple implementations.

What is a PHP Interface?

In PHP, an interface is a structure that defines a contract. Unlike classes, interfaces cannot contain concrete methods (methods with a body). Instead, they specify method signatures that implementing classes must fulfill. This allows for multiple, different implementations while ensuring consistency in the method signatures.

Defining an Interface

To define an interface in PHP, use the interface keyword. Within the interface, declare methods without bodies. Here's an example:

Implementing an Interface

Classes that implement an interface must define all of the interface's methods. Use the implements keyword to implement an interface. Here's how you can implement the Logger interface:

Benefits of Using Interfaces

Interfaces provide several advantages in software development:

Consistency: All implementing classes share the same method signatures, ensuring consistency.
Flexibility: Different classes can implement the same interface in diverse ways.
Decoupling: Interfaces help reduce dependencies between components, promoting a cleaner architecture.

Interface Inheritance

Interfaces can inherit from other interfaces, allowing for a more organized structure. Here's an example:

Conclusion

PHP interfaces are powerful tools for defining a contract in your code, ensuring that different classes adhere to a specific set of methods. By promoting consistency and flexibility, they are vital in building extensible and maintainable applications.

Basics

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