Can Interface Contain Concrete Methods?


Interfaces cannot have any concrete methods. If you need the ability to have abstract method definitions and concrete methods then you should use an abstract class.



CAN interface have constructors?

No, you cannot have a constructor within an interface in Java. You can have only public, static, final variables and, public, abstract, methods as of Java7. From Java8 onwards interfaces allow default methods and static methods. From Java9 onwards interfaces allow private and private static methods.


Can interface be static?

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.


Does interface contain only abstract methods?

Yes, Interfaces can only have abstract methods. In the Java programming language, an interface is a reference type, similar to a class, that can contain only constants, method signatures, default methods, static methods, and nested types. Method bodies exist only for default methods and static methods.


Can an interface have regular methods?

It cannot have a method body. Java Interface also represents the IS-A relationship. Like a class, an interface can have methods and variables, but the methods declared in an interface are by default abstract (only method signature, no body). Interfaces specify what a class must do and not how.


Can an interface have non abstract methods?

Interface methods are by definition public and abstract, so you cannot have non-abstract methods in your interface.


Can interface be protected in Java?

Protecting a constructor prevents the users from creating the instance of the class, outside the package. During overriding, when a variable or method is protected, it can be overridden to other subclass using either a public or protected modifier only. Outer class and interface cannot be protected.


Are interfaces always static?

Interface variables are static because java interfaces cannot be instantiated on their own. The value of the variable must be assigned in a static context in which no instance exists.


CAN interface have methods C#?

Like a class, Interface can have methods, properties, events, and indexers as its members. But interfaces will contain only the declaration of the members. The implementation of the interface's members will be given by class who implements the interface implicitly or explicitly.


Can interface contain concrete methods?

Interfaces cannot have any concrete methods. If you need the ability to have abstract method definitions and concrete methods then you should use an abstract class.


Can an interface have no methods?

Yes, you can write an interface without any methods. These are known as marking interfaces or, tagging interfaces. A marker interface i.e. it does not contain any methods or fields by implementing these interfaces a class will exhibit a special behavior with respect to the interface implemented.


CAN interface have abstract methods?

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).


Dated : 19-Jul-2022

Category : Education

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