Object Oriented Programming Questions
The main difference between an abstract class and an interface in Object-Oriented Programming (OOP) is that an abstract class can have both implemented and unimplemented methods, while an interface can only have unimplemented methods.
An abstract class serves as a blueprint for other classes and can contain both regular methods with implementations and abstract methods without implementations. It can also have instance variables and constructors. However, an abstract class cannot be instantiated, meaning you cannot create objects directly from it. Instead, it is meant to be extended by other classes, which must provide implementations for the abstract methods.
On the other hand, an interface is a collection of abstract methods that define a contract for classes to follow. It only contains method signatures without any implementations. An interface can also include constant variables. Classes can implement multiple interfaces, allowing them to inherit the method signatures and define their own implementations. Unlike abstract classes, interfaces cannot have instance variables or constructors.
In summary, while both abstract classes and interfaces provide a way to define common behavior for classes, abstract classes can have both implemented and unimplemented methods, while interfaces can only have unimplemented methods.