Attributes of Interface

Question

List out the attributes of an Interface.

Answer 1

An Interface is a template which holds only the signature of methods. The signature of method includes type of parameters, number of parameter (value, reference, or output), and also the order of parameters. An interface has no implementation on its own as it holds only the definition of methods without any body. An interface is defined by using the “interface” keyword. Also, you cannot instantiate an interface.

The features of an attributes are as follows:

a) An interface is used for implementing multiple inheritance within the code. This feature of an interface is different from that of the abstract classes since a class cannot derive the features of more than one class but can easily implement multiple interfaces.
b) It defines a particular set of methods and their arguments.
c) Variables in the interface must be declared as static, public, and final while methods must be public and abstract.
d) A class implementing an interface need to implement all of its methods.
e) An interface can be derived from more than one interface.