Runtime polymorphism execution in C Sharp (C#) - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a base class method that can be overridden.

C Sharp (C#)

public class Animal {
    public virtual void Speak() {
        Console.[1]("Animal speaks");
    }
}

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ADisplay

BPrint

COutput

DWriteLine

Attempts:

3 left

💡 Hint

Common Mistakes

Using methods that do not exist in Console class like Print or Display.

The Console.WriteLine method prints text to the console. It is used here to show the base class message.

2fill in blank

medium

Complete the code to override the Speak method in the derived class.

C Sharp (C#)

public class Dog : Animal {
    public override void [1]() {
        Console.WriteLine("Dog barks");
    }
}

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ASpeak

BTalk

CSound

DMakeNoise

Attempts:

3 left

💡 Hint

Common Mistakes

Using a different method name that does not override the base method.

The derived class overrides the base class method named Speak to provide its own behavior.

3fill in blank

hard

Fix the error in calling the Speak method using a base class reference to a derived class object.

C Sharp (C#)

Animal myAnimal = new Dog();
myAnimal.[1]();

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ABark

BTalk

CSpeak

DMakeSound

Attempts:

3 left

💡 Hint

Common Mistakes

Calling a method that only exists in the derived class or using wrong method names.

The base class reference calls the Speak method, which is overridden by the derived class. This demonstrates runtime polymorphism.

4fill in blank

hard

Fill both blanks to create a base class reference to a derived class object and call the overridden method.

C Sharp (C#)

Animal [1] = new [2]();
[1].Speak();

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AmyAnimal

BDog

CAnimal

DanimalObj

Attempts:

3 left

💡 Hint

Common Mistakes

Using the base class name for the object creation or mismatching variable names.

The variable myAnimal is declared as type Animal but refers to a new Dog object. Calling Speak uses the overridden method in Dog.

5fill in blank

hard

Fill all three blanks to implement runtime polymorphism with two derived classes overriding the base method.

C Sharp (C#)

public class Cat : Animal {
    public override void [1]() {
        Console.WriteLine("Cat meows");
    }
}

Animal [2] = new Dog();
Animal [3] = new Cat();
[2].Speak();
[3].Speak();

Drag options to blanks, or click blank then click option'

ASpeak

BdogAnimal

CcatAnimal

DMakeSound

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong method names or inconsistent variable names.

The Cat class overrides Speak. Two variables of type Animal refer to Dog and Cat objects. Calling Speak on each shows runtime polymorphism.