Question

what role does interface play?

Answer 1

i even dont even know what is interface is

Answer 2

Newcomers to the Java language often experience confusion. Their bafflement is largely due to Java's palette of exotic language features, such as generics and lambdas. However, even simpler features such as interfaces can be puzzling.

Recently, I confronted a question on why Java supports interfaces (via interfaceand implements keywords). When I began to learn Java in the 1990s, this question was often answered by stating that interfaces get around Java's lack of support for multiple implementation inheritance (child classes inheriting from multiple parent classes). However, interfaces serve as much more than a kludge. In this post, I present the six roles that interfaces play in the Java language.