Question

Using the provided Animal class and Zoo class (found here), write a method in class Zoo that returns the average age for a given animal type. You may not assume all elements in the array “animals" have been constructed. If there are no animals in the array with the type then return 0.0. Along with the solution make sure to include a Solution Description (150-300 words) or else no points will be awarded. (25pts).

Provided code Animal.java:

public class Animal
{
   private String type;
   private double age;
  
   public Animal(String aT, double anA)
   {
       this.type = aT;
       if(anA >= 0)
       {
           this.age = anA;
       }
   }
   public String getType()
   {
       return this.type;
   }
   public double getAge()
   {
       return this.age;
   }
}

Provided code Zoo.java:

public class Zoo {
   private Animal[] animals;
   public void setAnimals(Animal[] a)
   {
       this.animals = a;
   }
  
   public double getAverageAge(String aType)
   {
//-----------------------------------------------
       //Write your code here

      
      
      
      
      
      
      
   }
}

Answer 1

As per the problem statement I have solve the problem. Please let me know if you have any doubts or you want me to modify the answer. And if you find this answer useful then don't forget to rate my answer as thumps up. Thank you! :)

import java.io.IOException;

public class Driver
{
    public static void main(String[] args) throws IOException {
        Animal animal = new Animal("Cat", "Kitty", 150.0, 10);
        Animal animal1 = new Animal("Rabbit", "Chiku", 100.5, 15);

        //Zoo class
        Zoo zoo = new Zoo();
        zoo.addAnimal(animal);
        zoo.addAnimal(animal1);

        // Print out info about the zoo:
        System.out.println(zoo);
    }
}

-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

public class Animal
{
    private String species;

    private String name;

    private double weight;

    private int age;

    //constructor
    public Animal()
    {
        this.species = "unknown";
        this.name = "noname";
        this.weight = 0.0;
        this.age = 0;
    }

    //animal constructor
    public Animal(String species, String name, double weight, int age)
    {
        this.species = species;
        this.name = name;
        this.weight = weight;
        this.age = age;
    }

    //get species
    public String getSpecies()
    {
        return this.species;
    }

    //get name
    public String getName()
    {
        return this.name;
    }

    //get weight
    public double getWeight()
    {
        return this.weight;
    }

    //get age
    public int getAge()
    {
        return this.age;
    }

   //toString method
    public String toString()
    {
        return String.format("%s, a %s. %.1f pounds, %d years old\n", this.name, this.species, this.weight, this.age);
    }
}
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

public class Zoo
{
    private Animal[] animals;

    private int currentIndex;

    //construcctor
    public Zoo()
    {
        this.animals = new Animal[1];
        this.currentIndex = 0;
    }

    //expand capacity of zoo
    private void expandArray()
    {
        int oldSize = animals.length;
        Animal[] newArray = new Animal[oldSize + 2];
        for (int i = 0; i < oldSize; ++i)
        {
            newArray[i] = this.animals[i];
        }
        this.animals = newArray;
    }

    //method to add animal
    public void addAnimal(Animal ani)
    {
        if (this.currentIndex == this.animals.length)
        {
            this.expandArray();
        }
        this.animals[this.currentIndex] = ani;
        currentIndex++;
    }

    //get total wigth
    public double getTotalWeight()
    {
        double result = 0.0;
        // Loop over all animals and sum the weight:
        for (int i = 0; i < currentIndex; ++i)
        {
            result += this.animals[i].getWeight();
        }
        return result;
    }

    //get average age
    public int getAverageAge()
    {
        if (currentIndex == 0)
        {
            return 0;
        }
        double totalAge = 0;
        for (int i = 0; i < this.currentIndex; i++)
        {
            Animal animal = this.animals[i];
            totalAge += animal.getAge();
        }
        return (int) (totalAge / currentIndex);
    }

    //get size
    public int getSize()
    {
        return this.currentIndex;
    }

    //get total age with name
    public int totalAgeWithName(String name)
    {
        int totalAge = 0;
        for (int i = 0; i < this.currentIndex; ++i)
        {
            // Only add age if the animal has the same name.
            Animal animal = this.animals[i];
            if (animal.getName().equalsIgnoreCase(name))
            {
                totalAge += animal.getAge();
            }
        }
        return totalAge;
    }

    //get animal
    public Animal[] getAnimals()
    {
        return animals;
    }

    //to string method
    public String toString()
    {
        String result = "Animals currently reside in the zoo: \n";
        for (int i = 0; i < this.currentIndex; ++i)
        {
            result += this.animals[i].toString();
        }
        return result;
    }
}
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Program Output:

Zoo [/IdeaProjects/Zoo) -.../src/Driver.java (Zoo] Main - the Q Zoo src Driver - Project - Zoo -/IdeaProjects/Zoo idea out src Animal Driver Zoo 1. Zoo.im illi External Libraries Scratches and Consoles Driver.javax Animaljavax Zoo.java import java.io.IOException; public class Driver Wow WNIO public static void main(String Il args) throws IOException { Animal animal = new Animal( species: "Cat", name: "Kitty", weight: 150.0, age: 10); Animal animall = new Animal( species: "Rabbit", name: "Chiku", weight: 100.5, age: 15); //Zoo class Zoo zoo = new Zoo(); zoo.addAnimal(animal); zoo.addAnimal(animali); // Print out info about the zoo: System.out.println(zoo); 15 16 17 } ] Run: Driver > maino Main x /Library/Java/JavavirtualMachines/jdk-9.0.4.jdk/Contents/Home/bin/java "-javaagent:/Applications/Intellij IDEA CE.app/Contents/lib/idea_rt.jar=51736/Applications/Intellij IDEA CE.app/Contents/bi Animals currently reside in the zoo: Kitty, a Cat. 150.0 pounds, 10 years old Chiku, a Rabbit. 100.5 pounds, 15 years old Process finished with exit code 0 Compilation completed successfully in 75 858 ms (moments ago) 7:23 TF UITE- A