Functional Interface

• As we know interface is a blueprint of a class. It has static constants and abstract methods. A Functional Interface is an interface that only has one abstract method. Interface methods are by default public, and abstract. Thus it is not required to add public abstract int sum(int a, int b); In java, Runnable is a Functional Interface that has only a run method.

@FunctionalInterface
interface GetSummation{
    int sum(int a, int b);
}