Kotlin/Java comparison

Java23Example.java

// from: https://gist.github.com/MichaelDrogalis/37af55273ea17f3255c750ae60fc98d4

import java.util.List;

public class Java23Example {
    record Person(String name, int age) {}

    public static void main(String[] args) {
        var people = List.of(
            new Person("Alice", 30),
            new Person("Bob", 25),
            new Person("Charlie", 40),
            new Person("David", 18)
        );

        var processedPeople = people.stream()
            .filter(person -> !person.name().equals("Bob"))
            .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.";
            case Person(String name, int age) -> name + " is middle-aged.";
        };
    }
}

kotlin.kt

data class Person(val name: String, val age: Int)

fun listPeople() =
    listOf(
        Person("Alice", 30),
        Person("Bob", 25),
        Person("Charlie", 40),
        Person("David", 18)
    ).filterNot { it.name == "Bob" }
     .map { it.copy(name = it.name.uppercase()) }
     .forEach { println(personInfo(it)) }

fun personInfo(person: Person) = when {
    person.age < 20 -> "${person.name} is a teenager."
    person.age in 20..39 -> "${person.name} is an adult."
    else -> "${person.name} is middle-aged."
}

kotlin2.kt

data class Person(val name: String, val age: Int)

fun listPeople() =
    listOf(
        Person("Alice", 30),
        Person("Bob", 25),
        Person("Charlie", 40),
        Person("David", 18)
    ).filterNot { it.name == "Bob" }
     .map { it.copy(name = it.name.uppercase()) }
     .forEach {
         when {
             it.age < 20 -> "${it.name} is a teenager."
             it.age in 20..39 -> "${it.name} is an adult."
             else -> "${it.name} is middle-aged."
         }.also {
                println(it)
         }
     }