record Person(String name, int age) {}

public static void main(String[] args) {

var people = List.of(

new Person("Alice", 30),

new Person("Bob", 15),

new Person("Charlie", 40),

new Person("David", 18)

);

var processedPeople = people.stream()

.filter(person -> person.age() >= 18)

.map(person -> new Person(person.name().toUpperCase(), person.age()))

.toList();

for (var person : processedPeople) {

System.out.println(personInfo(person));

}

}

static String personInfo(Person person) {

return switch (person) {

case Person(String name, int age) when age < 20 -> name + " is a teenager.";

case Person(String name, int age) when age >= 20 && age < 40 -> name + " is an adult.";

default -> person.name() + " is middle-aged.";

};

}