Question

What is Functional Interface in Java 8?

Answer 1

A functional interface is an interfacethat contains only one abstract method. They can have only one functionality to exhibit. ... Runnable, ActionListener, Comparable are some of the examples of functionalinterfaces. Before Java 8, we had to create anonymous inner class objects or implement these interfaces.

Answer 2

Answer:

A functional interface is an interface that incorporates only one abstract method. They could have only one capability to exhibit.

Explanation:

Java has all the time remained an Object-Oriented Programming language. By object-orientated programming language, we will claim that the whole thing present withinside the Java programming language rotates in the course of the Objects, besides for a number of the primitive information types and primitive strategies for integrity and simplicity. There are no completely capabilities found in a programming language referred to as Java. Functions withinside the Java programming language are a part of a magnificence, and if a person desires to use them, they should use the magnificence or object of the magnificence to name any function.

From Java 8 onwards, lambda expressions may be used to symbolize the example of a functional interface. A functional interface could have any wide variety of default strategies. Runnable, ActionListener, Comparable are a number of the examples of functional interfaces.