What is the difference between abstract and interface in Java ?

Answer 1

Basically, in Java you can implement as many interfaces as you'd like. On the other hand a class can only extend one abstract class.

Answer 2

Here are some explanations with examples:
https://www.google.de/amp/s/www.geeksforgeeks.org/difference-between-abstract-class-and-interface-in-java/amp/

Answer 3

interface is a specific class which is fully abstract & u don't need to use the keyword abstract for every single method and property inside an interface.

Answer 4

Abstract Class:

*Abstract classes have a default constructor and it is called whenever the concrete subclass is instantiated.

*Contains Abstract methods as well as Non-Abstract methods.

*The class which extends the Abstract class shouldn’t require implementing all the methods, only Abstract methods need to be implemented in the concrete sub-class.

*Abstract Class contains instance variables.

Interface:

*Doesn’t have any constructor and couldn’t be instantiated.

*Abstract method alone should be declared.

*Classes which implement the interface should provide the implementation for all the methods.

*The interface contains only constants.

Answer 5

One of the differences between them:
Abstract class can provide method body while interface cannot

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