Practice›Java Fundamentals›Module 7. Inheritance & Polymorphism›7.4 Polymorphism

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7.4 Polymorphism — describe all animals

Total: 0 / 3 pts

Practice mode — check each part and get hints as you go.

Task

Fill in describeAll so that it returns the describe() of every animal, joined by newlines.

The array holds a Dog and a Cat, but its type is Animal[] — each element still runs its own version of describe(). That is polymorphism.

Your solution

class Animal {
    private String name;

    public Animal(String name) {
        this.name = name;
    }

    public String getName() {
        return name;
    }

    public String describe() {
        return name + " is an animal";
    }
}

class Dog extends Animal {
    public Dog(String name) {
        super(name);
    }

    @Override
    public String describe() {
        return getName() + " is a dog";
    }
}

class Cat extends Animal {
    public Cat(String name) {
        super(name);
    }

    @Override
    public String describe() {
        return getName() + " is a cat";
    }
}

public class Main {

    public static String describeAll(Animal[] animals) {
        // join every describe() with a newline between them

    }

    public static void main(String[] args) {
        Animal[] zoo = {new Dog("Rex"), new Cat("Kit")};
        System.out.println(describeAll(zoo));
    }
}

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