Can we perform multiple inheritence in class

Since multiple inheritance is bad (it makes the source more complicated) C# does not provide such a pattern directly. But sometimes it would be helpful to have this ability.

C# and the .net CLR have not implemented MI because they have not concluded how it would inter-operate between C#, VB.net and the other languages yet, not because "it would make source more complex"

MI is a useful concept, the un-answered questions are ones like:- "What do you do when you have multiple common base classes in the different superclasses?

Perl is the only language I've ever worked with where MI works and works well. .Net may well introduce it one day but not yet, the CLR does already support MI but as I've said, there are no language constructs for it beyond that yet.

Until then you are stuck with Proxy objects and multiple Interfaces instead :(

Consider just using composition instead of trying to simulate Multiple Inheritance. You can use Interfaces to define what classes make up the composition, eg: ISteerable implies a property of type SteeringWheel, IBrakable implies a property of type BrakePedal, etc.

Once you've done that, you could use the Extension Methods feature added to C# 3.0 to further simplify calling methods on those implied properties, eg:

public interface ISteerable { SteeringWheel wheel { get; set; } }
public interface IBrakable { BrakePedal brake { get; set; } }
public class Vehicle : ISteerable, IBrakable
{
public SteeringWheel wheel { get; set; }
public BrakePedal brake { get; set; }
public Vehicle() { wheel = new SteeringWheel(); brake = new BrakePedal(); }
}
public static class SteeringExtensions
{
public static void SteerLeft(this ISteerable vehicle)
{
vehicle.wheel.SteerLeft();
}
}
public static class BrakeExtensions
{
public static void Stop(this IBrakable vehicle)
{
vehicle.brake.ApplyUntilStop();
}
}
public class Main
{
Vehicle myCar = new Vehicle();
public void main()
{
myCar.SteerLeft();
myCar.Stop();
}
}

Since multiple inheritance is bad (it makes the source more complicated) C# does not provide such a pattern directly. But sometimes it would be helpful to have this ability.

C# and the .net CLR have not implemented MI because they have not concluded how it would inter-operate between C#, VB.net and the other languages yet, not because "it would make source more complex"

MI is a useful concept, the un-answered questions are ones like:- "What do you do when you have multiple common base classes in the different superclasses?

Until then you are stuck with Proxy objects and multiple Interfaces instead :(

Once you've done that, you could use the Extension Methods feature added to C# 3.0 to further simplify calling methods on those implied properties, eg:

public interface ISteerable { SteeringWheel wheel { get; set; } }
public interface IBrakable { BrakePedal brake { get; set; } }
public class Vehicle : ISteerable, IBrakable
{
public SteeringWheel wheel { get; set; }
public BrakePedal brake { get; set; }
public Vehicle() { wheel = new SteeringWheel(); brake = new BrakePedal(); }
}
public static class SteeringExtensions
{
public static void SteerLeft(this ISteerable vehicle)
{
vehicle.wheel.SteerLeft();
}
}
public static class BrakeExtensions
{
public static void Stop(this IBrakable vehicle)
{
vehicle.brake.ApplyUntilStop();
}
}
public class Main
{
Vehicle myCar = new Vehicle();
public void main()
{
myCar.SteerLeft();
myCar.Stop();
}
}

4 Replies

Know the answer? Post it — somebody with the same question will find it here.

Hamid Khan9y ago
you can not directly do it but with the help of interface you can achive
0
Nilesh Shah9y ago
I think your question suits more to the inverviews section, not here
0
Hassan Uddin Mughal9y ago
Sure you can perform multiple inheritance but only in C++ and Python. If you are using Java or C# etc. multiple inheritance is not allowed.
0
Manikandan Murugesan9y ago
Since multiple inheritance is bad (it makes the source more complicated) C# does not provide such a pattern directly. But sometimes it would be helpful to have this ability.

C# and the .net CLR have not implemented MI because they have not concluded how it would inter-operate between C#, VB.net and the other languages yet, not because "it would make source more complex"

MI is a useful concept, the un-answered questions are ones like:- "What do you do when you have multiple common base classes in the different superclasses?

Perl is the only language I've ever worked with where MI works and works well. .Net may well introduce it one day but not yet, the CLR does already support MI but as I've said, there are no language constructs for it beyond that yet.

Until then you are stuck with Proxy objects and multiple Interfaces instead :(

Consider just using composition instead of trying to simulate Multiple Inheritance. You can use Interfaces to define what classes make up the composition, eg: ISteerable implies a property of type SteeringWheel, IBrakable implies a property of type BrakePedal, etc.

Once you've done that, you could use the Extension Methods feature added to C# 3.0 to further simplify calling methods on those implied properties, eg:
public interface ISteerable { SteeringWheel wheel { get; set; } }

public interface IBrakable { BrakePedal brake { get; set; } }

public class Vehicle : ISteerable, IBrakable
{
    public SteeringWheel wheel { get; set; }

    public BrakePedal brake { get; set; }

    public Vehicle() { wheel = new SteeringWheel(); brake = new BrakePedal(); }
}

public static class SteeringExtensions
{
    public static void SteerLeft(this ISteerable vehicle)
    {
        vehicle.wheel.SteerLeft();
    }
}

public static class BrakeExtensions
{
    public static void Stop(this IBrakable vehicle)
    {
        vehicle.brake.ApplyUntilStop();
    }
}


public class Main
{
    Vehicle myCar = new Vehicle();

    public void main()
    {
        myCar.SteerLeft();
        myCar.Stop();
    }
}
0