Difference Between Class and Interface in Java

In this post, we will understand the difference between class and an interface in Java.

Class

• It tells about the attributes and behaviours that an object needs to possess.

• It can contain abstract methods as well as normal methods.

• Keyword to create it is ‘class’.

• It can be instantiated.

• It doesn’t support multiple inheritance.

• It can inherit a class.

• The name of the class’s parent (if any) is preceded by the keyword ‘extends’.

• The members in a class can be public, private or protected.

• The class body is surrounded by ‘{‘ and ‘}’.

• Variables could be static or final or normal variables.

Interface

• It contains behaviours that are implemented by a class.

• Keyword to create it is ‘interface’.

• It can’t be instantiated.

• It supports multiple inheritance.

• It can contain abstract methods only.

• It uses’ extends’ to inherit an interface.

• All variables are static and final.

• It can’t inherit a class.

• It is a blueprint for the class.

• It tells what a class must do, not how it should achieve it.

• The members of an interface are public by default.