Lambda Expression

import java.util.*;

public class LambdaExample {
    public static void main(String[] args) {
        List<String> names = Arrays.asList("Alice", "Bob", "Charlie");
        
        // Using lambda expression
        names.forEach(name -> System.out.println(name));
        
        // Using method reference
        names.forEach(System.out::println);
    }
}

Functional Interface

@FunctionalInterface
interface MathOperation {
    int operate(int a, int b);
}

public class FunctionalInterfaceExample {
    public static void main(String[] args) {
        MathOperation addition = (a, b) -> a + b;
        MathOperation subtraction = (a, b) -> a - b;
        
        System.out.println("10 + 5 = " + operate(10, 5, addition));
        System.out.println("10 - 5 = " + operate(10, 5, subtraction));
    }
    
    private static int operate(int a, int b, MathOperation mathOperation) {
        return mathOperation.operate(a, b);
    }
}