Interview Questions - Core Java

53.
What is a Marker Interface?
An Interface which doesn't have any declaration inside but still enforces a mechanism.

54.
Which object oriented Concept is achieved by using overloading and overriding?
Polymorphism.

55.
Why does Java not support operator overloading?
Operator overloading makes the code very difficult to read and maintain. To maintain code simplicity, Java doesn't support operator overloading.

56.
Can we define private and protected modifiers for variables in interfaces?
No.