Interface vs abstract class decision in C Sharp (C#) - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare an interface named IShape.

C Sharp (C#)

public interface [1] { void Draw(); }

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AShape

BIShape

CAbstractShape

DShapeInterface

Attempts:

3 left

💡 Hint

Common Mistakes

Using a class name instead of an interface name.

Not following the naming convention for interfaces.

The interface name should start with 'I' by convention, so 'IShape' is correct.

2fill in blank

medium

Complete the code to declare an abstract class named Shape.

C Sharp (C#)

public abstract class [1] { public abstract void Draw(); }

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AShape

BIShape

CAbstractShape

DShapeInterface

Attempts:

3 left

💡 Hint

Common Mistakes

Using interface naming for abstract classes.

Confusing interface and abstract class names.

The abstract class should be named 'Shape' without the 'I' prefix.

3fill in blank

hard

Fix the error in this class declaration that tries to inherit from an interface and an abstract class.

C Sharp (C#)

public class Circle : [1], IShape { public override void Draw() { } }

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ACircleBase

BIShape

CAbstractShape

DShape

Attempts:

3 left

💡 Hint

Common Mistakes

Trying to inherit from multiple classes.

Using interface name where abstract class is expected.

The class should inherit from the abstract class 'Shape' and implement the interface 'IShape'.

4fill in blank

hard

Fill both blanks to complete the interface and abstract class usage correctly.

C Sharp (C#)

public interface [1] { void Draw(); } public abstract class [2] { public abstract void Draw(); }

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

AIShape

BShape

CDrawable

DAbstractDrawable

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing interface and class naming conventions.

Using unrelated names for interface or abstract class.

The interface is named 'IShape' and the abstract class is named 'Shape' to follow conventions.

5fill in blank

hard

Fill all three blanks to implement a class that inherits from an abstract class and implements an interface.

C Sharp (C#)

public interface [1] { void Draw(); } public abstract class [2] { public abstract void Draw(); } public class [3] : [2], [1] { public override void Draw() { } }

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

AIShape

BShape

CCircle

DDrawable

Attempts:

3 left

💡 Hint

Common Mistakes

Using interface name as class name.

Not overriding abstract methods properly.

The interface is 'IShape', the abstract class is 'Shape', and the class implementing both is 'Circle'.