Try It Yourself - SyntaxStudy Editor

HTML / CSS / JS

import java.util.*;
import java.util.stream.*;

public class OptionalAndTerminalDemo {
    record Product(String name, double price, int stock) {}

public static void main(String[] args) {
        List<Product> products = List.of(
            new Product("Laptop",  999.99, 5),
            new Product("Mouse",    29.99, 0),
            new Product("Keyboard", 79.99, 12),
            new Product("Monitor", 349.99, 3)
        );

// findFirst returns Optional
        Optional<Product> cheapest = products.stream()
            .filter(p -> p.stock() > 0)
            .min(Comparator.comparingDouble(Product::price));

cheapest.ifPresent(p ->
            System.out.println("Cheapest in stock: " + p.name() + " $" + p.price()));

// orElse / orElseThrow
        String name = products.stream()
            .filter(p -> p.price() > 500 && p.stock() > 0)
            .map(Product::name)
            .findFirst()
            .orElse("No expensive item in stock");
        System.out.println(name);

// anyMatch / allMatch / noneMatch
        boolean anyOutOfStock = products.stream().anyMatch(p -> p.stock() == 0);
        boolean allHavePrice  = products.stream().allMatch(p -> p.price() > 0);
        System.out.println("Any out of stock: " + anyOutOfStock);
        System.out.println("All have price:   " + allHavePrice);

// Stream.iterate — first 8 powers of 2
        List<Integer> powers = Stream.iterate(1, n -> n * 2)
            .limit(8)
            .collect(Collectors.toList());
        System.out.println("Powers of 2: " + powers);

// Stream.generate — 5 random doubles
        Stream.generate(Math::random)
            .limit(5)
            .map(d -> String.format("%.4f", d))
            .forEach(System.out::println);
    }
}