Can you inherit multiple interfaces in c

Option 2: If the class does not wish to provide Implementation for all the members inherited from the interface, then the class has to be marked as abstract. A class inherits from 2 interfaces and both the interfaces have the same method name as shown below. How should the class implement the drive method for both Car and Bus interfaces?

By using explicitly Interface Implementation. To implement the Drive method use the fully qualified name as shown in the example below. To call the respective interface drive method typecast the demo object to the respective interface and then call the drive method.

I hope this article will help you with your need. I would like to have your feedback. Please post your feedback, question, or comments about this Multiple Inheritance using Interface in C article. Your email address will not be published. Skip to content. 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. C and the. 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. I created a C post-compiler that enables this kind of thing:. You could have one abstract base class that implements both IFirst and ISecond, and then inherit from just that base.

With C 8 now you practically have multiple inheritance via default implementation of interface members:. We all seem to be heading down the interface path with this, but the obvious other possibility, here, is to do what OOP is supposed to do, and build up your inheritance tree If this particular approach doesn't quite fit the bill the we simply create new classes based on the required objects Instead it was easier to simply make static "functions that call functions that call functions" in different modular varieties as a sort of OOP replacement.

The solution I was working on was the "spell system" for a RPG where effects need to heavily mix-and-match function calling to give an extreme variety of spells without re-writing code, much like the example seems to indicate.

Most of the functions can now be static because I don't necessarily need an instance for spell logic, whereas class inheritance can't even use virtual or abstract keywords while static.

Interfaces can't use them at all. Coding seems way faster and cleaner this way IMO. If you're just doing functions, and don't need inherited properties , use functions. If you can live with the restriction that the methods of IFirst and ISecond must only interact with the contract of IFirst and ISecond like in your example In practice, this is rarely the case. So the basic idea is that you define the required implementation in the interfaces Anytime you need to "add methods to the interface" instead you add an extension method.

Yes using Interface is a hassle because anytime we add a method in the class we have to add the signature in the interface. Also, what if we already have a class with a bunch of methods but no Interface for it? And the worst thing is, we have to implement all methods in the Interfaces in the child class if the child class is to inherit from the multiple interface.

By following Facade design pattern we can simulate inheriting from multiple classes using accessors. Not quite the same but it is practical. This is along the lines of Lawrence Wenham's answer, but depending on your use case, it may or may not be an improvement -- you don't need the setters. From this point, basically all Person code goes into IGetPerson, not into IPerson, other than new ivars, which have to go into both. And in using such code, you don't have to be concerned about whether or not your IGetPerson object is itself actually an IPerson.

Multiple inheritance is one of those things that generally causes more problems than it solves. The biggest problem is what to do if you inherit multiple classes that have a method with the same signature that the inheritee doesn't implement.

Which class's method should it choose? Or should that not compile? There is generally another way to implement most things that doesn't rely on multiple inheritance. Although inheritance provides for both features, it is not hard to imagine circumstances where either could be of use without the other.

Any CLR-compliant language, however, will allow the use of interfaces which provide the second feature of interfaces substitutability without the first member reuse. Since the question of multiple inheritance MI pops up from time to time, I'd like to add an approach which addresses some problems with the composition pattern.

This can be expressed, by adding a container reference to BaseClass in the First and Second implementation:. Things become more complicated, when protected interface elements from BaseClass are referenced or when First and Second would be abstract classes in MI, requiring their subclasses to implement some abstract parts.

Stack Overflow for Teams — Collaborate and share knowledge with a private group. Is this page helpful? Yes No. Any additional feedback? Skip Submit. This is the simple mathematical operation program demonstrating how multiple inheritance can be achieved in C using Interface Concept. Kiran Kumar Talikoti Updated date May 24, Multiple Inheritance in C. Generic; using System. Linq; using System.