Can interface implement many interface?

Yes, we can do it. An interface can extend multiple interfaces in Java.

Can an interface inherit an interface?

Interfaces can inherit from one or more interfaces. … When interfaces declare a default implementation of a method, any class implementing that interface inherits that implementation (You need to cast the class instance to the interface type to access the default implementation on the Interface member).

CAN interface have implementations?

All methods of an Interface do not contain implementation (method bodies) as of all versions below Java 8. … Interfaces cannot be instantiated, but rather are implemented. A class that implements an interface must implement all of the non-default methods described in the interface, or be an abstract class.

Which interface Cannot extend interface?

Java has Iterable interface which is extended by Collection . The Collection is further extended by List , Queue and Set which has their different-different implementations but the unique thing notice is that the Map interface doesn’t extend Collection interface.

Can interface inherit multiple interfaces?

An interface can extend other interfaces, just as a class subclass or extend another class. However, whereas a class can extend only one other class, an interface can extend any number of interfaces.

CAN interfaces have code?

Since Java 8, methods can be implemented ( can have a code body ) in an interface if only if it is declared static or default. … Abstract methods cannot have a body; all they can have is a method signature as shown in the example above. Variables are not allowed in interface.

CAN interface have static methods?

Static methods in an interface since java8

Since Java8 you can have static methods in an interface (with body). You need to call them using the name of the interface, just like static methods of a class.

Can an interface have fields Java?

A Java interface is a bit like a Java class, except a Java interface can only contain method signatures and fields. A Java interface is not intended to contain implementations of the methods, only the signature (name, parameters and exceptions) of the method.

CAN interfaces 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.

CAN interfaces have default methods?

Interfaces can have default methods with implementation in Java 8 on later. Interfaces can have static methods as well, similar to static methods in classes. Default methods were introduced to provide backward compatibility for old interfaces so that they can have new methods without affecting existing code.

CAN interface have variables?

An interface can have methods and variables just like the class but the methods declared in interface are by default abstract (only method signature, no body, see: Java abstract method). Also, the variables declared in an interface are public, static & final by default.

Can I implement multiple interfaces in C#?

C# allows the implementation of multiple interfaces with the same method name.

Can interface be internal?

The class that implements that interface is also internal. In the implementation of the interface, I make all the members that I implement, internal.

Can we create object of interface?

No, you cannot instantiate an interface. Generally, it contains abstract methods (except default and static methods introduced in Java8), which are incomplete.

How do you implement an interface?

To declare a class that implements an interface, you include an implements clause in the class declaration. Your class can implement more than one interface, so the implements keyword is followed by a comma-separated list of the interfaces implemented by the class.

CAN interface have private methods in C#?

Interface cannot include private, protected, or internal members. All the members are public by default. Interface cannot contain fields, and auto-implemented properties. A class or a struct can implement one or more interfaces implicitly or explicitly.

CAN interface have constructors?

No, you cannot have a constructor within an interface in Java. … From Java8 onwards interfaces allow default methods and static methods. From Java9 onwards interfaces allow private and private static methods.