Sample program to introduce functional interfaces with lambda notation

Lambdas.java

package com.ucguy4u.functional.java;

import java.util.function.*;

/**
 *
 * @author chauhanuday
 */
public class Lambdas {

	public static void main(String[] args) {
		// using the test method of Predicate
		System.out.println("Predicate example :");
		Predicate<String> stringLen = (s) -> s.length() < 10;
		System.out.println(stringLen.test("Apples") + " - Apples is less than 10");

		// Consumer example uses accept method
		System.out.println("\nConsumer example :");
		Consumer<String> consumerStr = (s) -> System.out.println(s.toLowerCase());
		consumerStr.accept("ABCDefghijklmnopQRSTuvWxyZ");

		// Function example
		System.out.println("\nFunction example :");
		Function<Integer, String> converter = (num) -> Integer.toString(num);
		System.out.println("\nlength of 26: " + converter.apply(26).length());

		// Supplier example
		System.out.println("\nSupplier example :");
		Supplier<String> s = () -> "Java is fun";
		System.out.println(s.get());

		// Binary Operator example
		System.out.println("\nBinaryOperator example :");
		BinaryOperator<Integer> add = (a, b) -> a + b;
		System.out.println("add 10 + 25: " + add.apply(10, 25));

		// Unary Operator example
		System.out.println("\nUnaryOperator example :");
		UnaryOperator<String> str = (msg) -> msg.toUpperCase();
		System.out.println(str.apply("This is my message in upper case"));
	}

}