What are the differences between abstract classes and interfaces? When would you choose one over the other, and why?

Question

Accepted Answer

Interfaces define a contract for classes to implement, while abstract classes can have both abstract and concrete methods.

Interfaces can only have abstract methods and constants, while abstract classes can have both abstract and concrete methods.
A class can implement multiple interfaces but can only inherit from one abstract class.
Interfaces are used for achieving multiple inheritance in Java, while abstract classes are used to define a common behavior for subclasses.
Interfaces are used to achieve loose coupling and provide a way to achieve abstraction in Java programming.
Example: An interface 'Shape' can have methods like 'calculateArea' and 'calculatePerimeter', while an abstract class 'Animal' can have concrete methods like 'eat' and 'sleep'.

Accepted Answer

Abstract class to be extended to the drived class and override

Interface - implement the method in our class

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