Explaination of Interface and Abstract classes.

Question

Accepted Answer

Interfaces and abstract classes are used for abstraction and defining contracts.

Interfaces are a collection of abstract methods that define a contract for a class to implement.
Abstract classes are classes that cannot be instantiated and can have both abstract and concrete methods.
Interfaces can be implemented by multiple classes, while a class can only inherit from one abstract class.
Interfaces are used for loose coupling and to achieve multiple inheritance-like behavior.
Abstract classes are used for code reuse and to provide a common implementation for subclasses.
Example: An interface 'Shape' can have methods like 'getArea' and 'getPerimeter', which can be implemented by classes like 'Circle' and 'Rectangle'.
Example: An abstract class 'Animal' can have a concrete method 'eat' and an abstract method 'makeSound', which can be implemented by subclasses like 'Dog' and 'Cat'.

Top GlobalLogic Software Engineer interview questions & answers