Explain the difference between abstract class and interface in object-oriented programming.

Explaining the Difference Between Abstract Class and Interface in Object-Oriented Programming

When it comes to object-oriented programming, the difference between an abstract class and an interface lies in their design and functionality.

Abstract Class

An abstract class is a class that cannot be instantiated on its own and may contain a mix of abstract and concrete methods. This means that it can have both method implementations and method declarations. Additionally, a class can only inherit from one abstract class, making it a way to provide a base implementation for subclasses.

Interface

On the other hand, an interface in object-oriented programming is a blueprint of a class that only contains method signatures and constants. Interfaces cannot have method implementations, only method declarations. Classes can implement multiple interfaces, allowing for a way to define a contract or behavior that a class must follow without specifying how it should be implemented.

Overall, the key difference between an abstract class and an interface is that an abstract class can have both abstract and concrete methods and supports single class inheritance, while an interface only contains method declarations and constants with support for multiple interface implementation.