Interview Questions - Core Java

41.
What is use of a abstract variable?
Variables can't be declared as abstract. only classes and methods can be declared as abstract.

42.
Can you create an object of an abstract class?
Not possible. Abstract classes can't be instantiated.

43.
Can a abstract class be defined without any abstract methods?
Yes it's possible. This is basically to avoid instance creation of the class.

44.
Class C implements Interface I containing method m1 and m2 declarations. Class C has provided implementation for method m2. Can i create an object of Class C?
No not possible. Class C should provide implementation for all the methods in the Interface I. Since Class C didn't provide implementation for m1 method, it has to be declared as abstract. Abstract classes can't be instantiated.