Method overriding with virtual and override in C Sharp (C#) - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

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

C Sharp (C#)

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

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

Avirtual

Boverride

Cstatic

Dsealed

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'override' in the base class method declaration.

Using 'static' which does not allow overriding.

Using 'sealed' which prevents overriding.

The virtual keyword allows a method to be overridden in a derived class.

2fill in blank

medium

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

C Sharp (C#)

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

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

Anew

Bsealed

Coverride

Dvirtual

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'virtual' instead of 'override' in the derived class.

Using 'new' which hides the base method but does not override.

Using 'sealed' which is not valid here.

The override keyword is used in the derived class to provide a new implementation of a virtual method.

3fill in blank

hard

Fix the error in the derived class method declaration to correctly override the base method.

C Sharp (C#)

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

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

Avirtual

Bsealed

Cstatic

Doverride

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'virtual' in the derived class method.

Using 'static' which is not allowed for overriding.

Omitting the override keyword.

To override a virtual method from the base class, the derived method must use the override keyword.

4fill in blank

hard

Fill both blanks to declare a virtual method in the base class and override it in the derived class.

C Sharp (C#)

public class Bird {
    public [1] void Fly() {
        Console.WriteLine("Flying");
    }
}

public class Sparrow : Bird {
    public [2] void Fly() {
        Console.WriteLine("Sparrow flying fast");
    }
}

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

Avirtual

Bstatic

Coverride

Dsealed

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'static' in either method which prevents overriding.

Using 'sealed' incorrectly.

Omitting the override keyword in the derived class.

The base class method must be virtual to allow overriding, and the derived class method must use override to replace it.

5fill in blank

hard

Fill all three blanks to override a virtual method and call the base method inside the override.

C Sharp (C#)

public class Vehicle {
    public [1] void Start() {
        Console.WriteLine("Vehicle starting");
    }
}

public class Car : Vehicle {
    public [2] void Start() {
        [3].Start();
        Console.WriteLine("Car starting with extra steps");
    }
}

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

Avirtual

Boverride

Cbase

Dsealed

Attempts:

3 left

💡 Hint

Common Mistakes

Not calling the base method inside the override.

Using 'sealed' incorrectly.

Omitting the override keyword in the derived method.

The base method is declared virtual. The derived method uses override and calls the base method with base.