Functional Interfaces with Lambdas in Java

Write a Java program to demonstrate the use of a functional interface with lambdas and method references

Operation is a functional interface with a single abstract method perform.
The Main class contains a static method add(int a, int b) which simply adds two integers and returns the result.
A lambda expression is used to create an instance of Operation for addition.
A method reference Main::add is used to create an instance of Operation for subtraction, referring to the add method in the Main class.
The perform method of each instance of Operation is called with different arguments to demonstrate addition and subtraction operations.

Source Code

@FunctionalInterface
interface Operation
{
	int perform(int a, int b);
}
 
public class Main
{
	public static int add(int a, int b)
	{
		return a + b;
	}
 
	public static void main(String[] args)
	{
		Operation addition = (a, b) -> a + b;
		Operation subtraction = Main::add;
 
		System.out.println("Addition : " + addition.perform(4, 3));
		System.out.println("Subtraction : " + subtraction.perform(10, 7));
	}
}

Output

Addition : 7
Subtraction : 17

Functional Interfaces with Lambdas in Java

Source Code

Output

Example Programs

Interface Programs in Java