equals() and hashCode() for a HashMap Key

import java.util.*;

public class EqualsHashCodeDemo {
    public static void main(String[] args) {
        Map<Person, String> roles = new HashMap<>();
        roles.put(new Person("Asha", 31), "admin");

        System.out.println(roles.get(new Person("Asha", 31)));     // admin  (an equal key finds the entry)
        System.out.println(roles.get(new Person("Asha", 32)));     // null   (a different age is a different key)
        System.out.println(new Person("Asha", 31).hashCode() == new Person("Asha", 31).hashCode());   // true
    }
}

// Immutable (final fields), so it is safe as a key. equals() and hashCode() use the same fields.
final class Person {
    private final String name;
    private final int age;

    Person(String name, int age) {
        this.name = name;
        this.age = age;
    }

    @Override
    public boolean equals(Object o) {
        return o instanceof Person other && age == other.age && Objects.equals(name, other.name);
    }

    @Override
    public int hashCode() {
        return Objects.hash(name, age);
    }
}