Difference Between Abstract class and Interface

Difference Between Abstract class and Interface.

Abstract Class	Interface
1. If we are talking about implementation but not completely (partially implementation) then go for abstract class.	1. If we does know anything about the implementation then we should go for the interface.
2. Every method present in abstract class need not be abstract ,it can be not abstract also.	2. Every method present inside interface is by default abstract.
3. Every method present in abstract class need not be public.	3. Every method present inside interface is by default public.
4. We can use any modifier for the method.	4. The following modifiers are not allowed for the interface methods: Strictfp , protected , final , native , static , private , synchronized .
5. No restriction for abstract class variables.	5. Every attribute present inside the interface is by default public , static and final.
6. No restriction for the abstract class variables.	6. Following modifiers cannot declares for the interface variables Private , protected , transient , volatile .
7. No restriction for the initialization of abstract class variables.	7. Compulsory initialize the variables whenever declaration.
8. Inside abstract class we can take instance and static block.	8. Inside interface we cannot take instance and static block.
9. Inside abstract class we can create constructor.	9. Inside interface we can not create constructor.