Question:

Consider the following classes:

public class Animal {
    protected String name;
    
    public Animal(String name) {
        this.name = name;
    }
    
    public String getName() {
        return name;
    }
    
    public void makeSound() {
        System.out.println("The animal makes a sound.");
    }
}

public class Cat extends Animal {
    public Cat(String name) {
        super(name);
    }
    
    public void makeSound() {
        System.out.println("Meow!");
    }
}

public class Dog extends Animal {
    public Dog(String name) {
        super(name);
    }
    
    public void makeSound() {
        System.out.println("Woof!");
    }
}

Now, suppose we have the following code:

public class Main {
    public static void main(String[] args) {
        Animal animal = new Animal("Generic Animal");
        Animal cat = new Cat("Tom");
        Animal dog = new Dog("Max");

        animal.makeSound();
        cat.makeSound();
        dog.makeSound();
        
        System.out.println(cat.getName());
        System.out.print(dog.getName());
    }
}

What will be the output of the code above? Explain each step in detail.

a) The animal makes a sound. Meow! Woof! Tom Max

b) Tom Max Meow! Woof!

c) The animal makes a sound. Woof! Meow! Tom Max

d) The animal makes a sound. Meow! Woof! Max Tom

Answer:

The correct answer is d) The animal makes a sound. Meow! Woof! Max Tom

Explanation:

In the code, we have defined three objects: animal, cat, and dog of type Animal, Cat, and Dog, respectively.

1. Animal animal = new Animal("Generic Animal");: Here, we create an Animal object named animal with the name "Generic Animal".

2. Animal cat = new Cat("Tom");: Here, we create a Cat object named cat with the name "Tom". Since Cat is a subclass of Animal, we can assign it to an Animal reference variable.

3. Animal dog = new Dog("Max");: Similar to the previous line, we create a Dog object named dog with the name "Max". Again, it can be assigned to an Animal reference variable.

4. animal.makeSound();: We call the makeSound() method on the animal object, which is of type Animal. The Animal class implements the default makeSound() method, which prints "The animal makes a sound." Therefore, the output will be "The animal makes a sound."

5. cat.makeSound();: We call the makeSound() method on the cat object, which is of type Cat. The Cat class overrides the makeSound() method from the Animal class and prints "Meow!". Therefore, the output will be "Meow!".

6. dog.makeSound();: We call the makeSound() method on the dog object, which is of type Dog. Similarly, the Dog class overrides the makeSound() method and prints "Woof!". Therefore, the output will be "Woof!".

7. System.out.println(cat.getName());: We call the getName() method on the cat object, which is of type Cat. The Cat class does not override the getName() method from the Animal class, so the implementation from the Animal class is used. It returns the name "Tom", and we print it using System.out.println(). Therefore, the output will be "Tom".

8. System.out.print(dog.getName());: We call the getName() method on the dog object, which is of type Dog. Similar to the previous step, the implementation from the Animal class is used since the Dog class does not override the getName() method. It returns the name "Max", and we print it using System.out.print(). Therefore, the output will be "Max".

Hence, the final output of the code will be "The animal makes a sound. Meow! Woof! Max Tom", which corresponds to option d).