In the attached program, the class Dog is defined.

See the definition of the class, and then write the test class method
public static String oldestDog(ArrayList<Dog> dogs)

which takes as its parameter a list of dogs. The method searches for the oldest dog's name and returns it.






import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Random;

public class Test{
    public static void main(String[] args){
        final Random r = new Random();
        
        
        String[] nt = {"Fifi","Jackie","Lassie","Rin-Tin-Tin","Snoopy","Scooby-Doo"};
        
        for (int testi = 1; testi <= 3; testi++) {
            System.out.println("Test " + testi);
            ArrayList<String> names = new ArrayList<String>(Arrays.asList(nt));
           
            int year = r.nextInt(100) + 1900;
            ArrayList<Dog> dogs = new ArrayList<>();
            while (!names.isEmpty()) {
                Dog k = new Dog(names.remove(r.nextInt(names.size())), year);
                year += r.nextInt(15) + 1;
                dogs.add(k);
            }
            Collections.shuffle(dogs);
            
            System.out.println("Dogs: " + dogs);
            System.out.println("Oldest dog: " + oldestDog(dogs));
            System.out.println("List after method call: " + dogs);
            System.out.println("");
        }
        
    }



    //ADD HERE
    public static String oldestDog(ArrayList<Dog> dogs) {
        int oldestDogYear = 9999;
        String oldestDogName = "";
        for (Dog dog: dogs) {
            // we want the smallest dog year (for the oldest dog)
            if (dog.getBirthyear() < oldestDogYear) {
                oldestDogYear = dog.getBirthyear();
                oldestDogName = dog.getName();
            }
        }
        return oldestDogName;
    }


    








}

class Dog {
    private String name;
    private int birthyear;

    
    public Dog(String name, int birthyear) {
        this.name = name;
        this.birthyear = birthyear;
    }

    public String getName() {
        return name;
    }

    public int getBirthyear() {
        return birthyear;
    }

    @Override
    public String toString() {
        return name + " (" + birthyear + ")";
    }   
}







Test 1
Dogs: [Lassie (2018), Snoopy (1995), Fifi (1993), Scooby-Doo (2013), Rin-Tin-Tin (2000), Jackie (2012)]
Oldest dog: Fifi
List after method call: [Lassie (2018), Snoopy (1995), Fifi (1993), Scooby-Doo (2013), Rin-Tin-Tin (2000), Jackie (2012)]

Test 2
Dogs: [Scooby-Doo (1931), Lassie (1937), Jackie (1961), Snoopy (1948), Fifi (1964), Rin-Tin-Tin (1976)]
Oldest dog: Scooby-Doo
List after method call: [Scooby-Doo (1931), Lassie (1937), Jackie (1961), Snoopy (1948), Fifi (1964), Rin-Tin-Tin (1976)]

Test 3
Dogs: [Scooby-Doo (1937), Fifi (1947), Snoopy (1931), Jackie (1921), Lassie (1962), Rin-Tin-Tin (1946)]
Oldest dog: Jackie
List after method call: [Scooby-Doo (1937), Fifi (1947), Snoopy (1931), Jackie (1921), Lassie (1962), Rin-Tin-Tin (1946)]