CCCPaste

3. Класс с несколькими полями

import java.util.Objects;

public class User {
    String name;
    int age;

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

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;

        User user = (User) o;
        return age == user.age && Objects.equals(name,user.name);
    }

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


public class Main {
    public static void main(String[] args) {
    User u1 = new User("Amir", 25);
        User u2 = new User("Amir", 25);
        User u3 = new User("Amir", 30);
        User u4 = new User(null, 25);
        User u5 = new User(null, 25);

        System.out.println(u1.equals(u2));
        System.out.println(u1.equals(u3));
        System.out.println(u4.equals(u5));
        System.out.println(u1.equals(u4));
    }
}