What is different between abstract class and interface in PHP?

Understanding the Difference between Abstract Class and Interface As an experienced tutor registered on UrbanPro.com specializing in PHP Training, let's delve into the key distinctions between abstract classes and interfaces in PHP. Abstract Class in PHP Definition: An abstract class is a class that cannot be instantiated on its own. It serves as a blueprint for other classes and may contain abstract methods. Usage: Used when a common base class needs to provide some common functionality to derived classes. Allows defining both abstract and non-abstract methods. Accessibility: Abstract classes can have a mix of abstract and concrete methods. Abstract methods are declared using the abstract keyword and are implemented by the derived classes. Inheritance: Supports single-class inheritance. Example: php abstract class Shape { abstract function getArea(); public function getColor() { return "Undefined"; } } Interface in PHP Definition: An interface is a collection of abstract methods with no implementation. Classes that implement an interface must provide the code for each method defined in the interface. Usage: Used when a contract needs to be enforced across multiple, unrelated classes. Allows achieving multiple inheritances in PHP. Accessibility: All methods declared in an interface must be public. No method in an interface can have a body. Inheritance: Supports multiple interface inheritance. Example: php interface ShapeInterface { public function getArea(); } Key Differences Instantiation: Abstract classes cannot be instantiated directly, while interfaces cannot be instantiated at all. Method Implementation: Abstract classes can have both abstract and non-abstract methods with some code implementation. Interfaces can only have abstract methods, and the implementing class must provide the implementation. Inheritance: Abstract classes support single-class inheritance. Interfaces support multiple interface inheritance, allowing a class to implement multiple interfaces. Accessibility: Abstract classes can have a mix of access modifiers for methods. All methods in an interface must be public. Conclusion Understanding the differences between abstract classes and interfaces in PHP is crucial for effective object-oriented programming. In PHP Training, grasping these concepts lays a solid foundation for designing scalable and maintainable code. read less