Is it right? An interface may contain abstract method.

Question

The fact is Interface only contains abstract methods and constants. So, I think: this statement: "An interface MAY contain abstract methods" is TRUE.

Answer 1

https://docs.oracle.com/javase/tutorial/java/IandI/interfaceDef.html

"The interface body can contain abstract methods, default methods, and static methods. An abstract method within an interface is followed by a semicolon, but no braces (an abstract method does not contain an implementation)."

I think it's a play on words, we don't have to use the abstract keyword to mark an interface method as abstract. If it has no implementation, it is implicitly abstract.

Answer 2

Yes you can say that it's true