Is it possible to create object for interface

Find centralized, trusted content and collaborate around the technologies you use most. Connect and share knowledge within a single location that is structured and easy to search. With that syntax, you create an anonymous class , which is perfectly legal. This means that the following class is being created:.

Then, the code in main compiles to internally use the newly-defined anonymous class:. It is anonymous class. Your check class is an interface. Anonymous class defines an implementation of given interface on the fly. So it saves you from creating a seperate class for Interface's implementation. This approach is only useful when you know you will never require this implementation any where else in the code.

You are creating an instance on the fly of anonymous class that implements the interface check. Related Articles. Basics of Java. Operators in Java. Packages in Java. Flow Control in Java. Loops in Java. Jump Statements in Java. Arrays in Java. Strings in Java. OOPS in Java.

Constructors in Java. Interfaces in Java. Keywords in Java. Exception Handling in Java. Collection Framework. Multi-threading in Java. If you define a reference variable whose type is an interface, any object you assign to it must be an instance of a class that implements the interface.

As an example, here is a method for finding the largest object in a pair of objects, for any objects that are instantiated from a class that implements Relatable :. By casting object1 to a Relatable type, it can invoke the isLargerThan method.

For example, say we want to create a Car and a Truck, but all our program wants to do is "start" them and "drive" them. To our program's "point of view" they are just Vehicles. Below are examples showing how we would write the code without interfaces, with interfaces, and then with a generic arrays of "Vehicles". The final example above shows the concept of Polymorphism. Polymorphism is the idea that an compile time coding time we don't know and often can't know what the actual type of object inside a variable will be.

In the vehicles array above, we don't know if vehicles[i] is a car, truck, bicycle, etc. In computer languages without polymorphism, we wouldn't be able to do anything with these objects. With polymorphism, the computer remembers what each is and when we say: "item. Polymorphism save the programmer a lot of time and effort in coding up "exceptional" conditions.

The computer does the work for us, a remembering what each object really is, and then b at run time, invoking the actual function associated with the current object. Sometimes, you will want to use a function specific to an underlying type.