Final answer:
No, we cannot have a non-abstract method inside an interface in Java. An interface in Java is a collection of abstract methods that define a contract that a class can implement.
Step-by-step explanation:
No, we cannot have a non-abstract method inside an interface in Java.
An interface in Java is a collection of abstract methods that define a contract that a class can implement.
Therefore, all methods inside an interface are abstract by default, and we cannot define a non-abstract method.