Implementing interfaces in C Sharp (C#) - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare that the class implements the interface.

C Sharp (C#)

public interface IAnimal {
    void Speak();
}

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

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AIAnimal

Bclass

Cinterface

DAnimal

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'class' instead of the interface name after the colon.

Trying to use 'interface' keyword after the class name.

The class Dog implements the interface IAnimal using a colon followed by the interface name.

2fill in blank

medium

Complete the code to implement the interface method correctly.

C Sharp (C#)

public interface IShape {
    double GetArea();
}

public class Square : IShape {
    private double side;
    public Square(double side) {
        this.side = side;
    }
    public double [1]() {
        return side * side;
    }
}

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AArea

BGetArea

CCalculateArea

DArea()

Attempts:

3 left

💡 Hint

Common Mistakes

Using a different method name than the interface.

Adding parentheses in the method name in the declaration.

The method name must exactly match the interface method GetArea to implement it.

3fill in blank

hard

Fix the error by completing the code to explicitly implement the interface method.

C Sharp (C#)

public interface ILogger {
    void Log(string message);
}

public class ConsoleLogger : ILogger {
    void [1].Log(string message) {
        Console.WriteLine(message);
    }
}

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AILogger

BLog

CConsoleLogger

DLogger

Attempts:

3 left

💡 Hint

Common Mistakes

Using the class name instead of the interface name.

Omitting the interface name prefix.

Explicit interface implementation requires prefixing the method with the interface name ILogger.

4fill in blank

hard

Fill both blanks to complete the interface and class implementation with a property.

C Sharp (C#)

public interface ICar {
    int [1] { get; set; }
}

public class Sedan : ICar {
    private int speed;
    public int [2] {
        get { return speed; }
        set { speed = value; }
    }
}

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ASpeed

Bspeed

DVelocity

Attempts:

3 left

💡 Hint

Common Mistakes

Using different property names in interface and class.

Using lowercase property name in interface but uppercase in class.

The property name must be the same in the interface and the class to implement it correctly.

5fill in blank

hard

Fill all three blanks to implement multiple interfaces with methods.

C Sharp (C#)

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

public interface ISwimmable {
    void [2]();
}

public class Duck : [3] {
    public void Fly() {
        Console.WriteLine("Flying");
    }
    public void Swim() {
        Console.WriteLine("Swimming");
    }
}

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AFly

BSwim

CIFlyable, ISwimmable

DDuck

Attempts:

3 left

💡 Hint

Common Mistakes

Using the class name instead of interface names after the colon.

Mismatching method names with interface declarations.

The class Duck implements both interfaces IFlyable and ISwimmable. The methods must match the interface method names.