Lambda example with single method interface implementation.

Functional interfaces are an interface with single abstract method. Lambdas are type of functional interfaces. Java API has many single method implementations like Comparator, Runnable, Callable, etc. Prior to Java-8, you can implement and initiaize them using anynomus class syntax.

In this page we have given a simple example on Lambda implementation on single method interface. We have taken Runnable interface for the example. It has only one method called "run". In the example notice that how lambda reduced multiple lines of code to single line:

package com.java2novice.lambda;

public class FuncIntLambdaEx {

	public static void main(String a[]) {

		// normal way of anonymous class implementation
		Runnable rnnObj = new Runnable() {

			@Override
			public void run() {
				System.out.println("Runnable interface with normal anonymous class implementation...");
			}
		};

		// anonymous class implementation with Lambda
		Runnable rnnObjLImpl = () -> System.out.println("Runnable interface with Lambda implementation...");

		rnnObj.run();
		rnnObjLImpl.run();
	}
}

Java-8 Lambda expression examples

1. Lambda expression syntax example
2. Lambda example with single method interface implementation.
3. Comparator example with Lambda implementation.
4. How to return lambda as an object?