how interface different from abstract class
1 Abstract classes can have methods with implementation whereas interface provides absolute abstraction and canât have any method implementations. 2  Abstract classes can have constructors but interfaces canât have constructors. 3  Abstract class have all the features of a normal java class except that we canât instantiate it.
1 Abstract classes can extend other class and implement interfaces but interface can only extend other interfaces. 2  We can run an abstract class if it has main() method but we canât run an interface because they canât have main method implementation.