Can we declare class inside interface in Java?
Can we declare class inside interface in Java?
Yes, you can define a class inside an interface. In general, if the methods of the interface use this class and if we are not using it anywhere else we will declare a class within an interface.
Can an inner class implement an interface?
A normal class can implement any number of interfaces but the anonymous inner class can implement only one interface at a time. A regular class can extend a class and implement any number of interfaces simultaneously.
CAN interface have class members?
All variables declared inside interface are implicitly public, static and final. All methods declared inside interfaces are implicitly public and abstract, even if you don’t use public or abstract keyword. Interface can extend one or more other interface. Interface cannot implement a class.
How do you write an interface inside class?
While implementing the interface, we mention the interface as c_name. i_name where c_name is the name of the class in which it is nested and i_name is the name of the interface itself. // interface inside a class. The access specifier in above example is default.
Can we declare static method in interface?
No,Because of static methods belolngs to a class not instance of class,and interfaces are not classes.In interface you define a behaviour taht has to be implemented in calss.So it is not possible to make a static method in interface.In java8 introduces static methods in interface.
What is nesting in Java?
In Java, it is possible to define a class within another class, such classes are known as nested classes. They enable you to logically group classes that are only used in one place, thus this increases the use of encapsulation, and creates more readable and maintainable code.
Can be declared inside interface declaration?
Be default, any variables declared inside interface is, public….Interview Question and Answers on Java Interface.
| Sr. No. | Abstract Classes | Interface |
|---|---|---|
| 1 | Contains members variables | All variables are actually constants |
| 2 | It can have constructors | Interface cannot have constructors |
Can we have inner interface?
We can declare interfaces as member of a class or another interface. Such an interface is called as member interface or nested interface. Interfaces (or classes) can have only public and default access specifiers when declared outside any other class (Refer this for details).
CAN interface have inner interface in Java?
Yes, we can do it. The definition of the nested interface in java is as follows: A nested interface is any interface whose declaration occurs within the body of another class or interface.
