Why .net does not support multiple inheritance????

Question

Hi friends... Why .net does not support multiple inheritance???? Thanks in advance....

Santhosh Kumar Jayaraman · Answer

Let me tell you a scenario. I have a class Shape1 It has CalcualteArea method Class Shape1 { public void CalculateArea() { // } } There is another class shape2 that one also has same method Class Shape2 { public void CalculateArea() { // } } Now i have a child class Circle, it derives from both SHape1 and shape2; public class Circle: Shape1,shape2 { } Now when i create object for Circle, and call the method, system doesnt know which calculate area method to be called.. Both has same signatures. So compiler will get confuse .thats why multiple inheritances are not allowed. But there can be multiple interfaces because interfaces dont ve methjod definition..Even both the interfaces have same method, both of them dont ve any implementation and always method in the child class will be executed.. Guess it would be clear.. check this link , it would have more details on the framework side. http://www.artima.com/intv/dotnetP.html

Akkiraju Ivaturi · Answer

To understand that you need to understand the Diamond problem first: The Diamond problem is an ambiguity that arises when two classes B and C inherit from Class A and class D inherits from both B and C. If a method in D calls a method defined in A(and does not override the method), and B and C have overridden that method differently, then from which class does it inherit: B or C? That is the reason why C# and Java languages does not support multiple inheritance.

sapana sharma · Answer

Basically, it seemed that both the .NET and Java designers did not allow multiple inheritance because they reasoned that adding MI added too much complexity to the languages while providing too little benefit . Different languages actually have different expectations for how MI works. For example, how conflicts are resolved and whether duplicate bases are merged or redundant. Before we can implement MI in the CLR, we have to do a survey of all the languages, figure out the common concepts, and decide how to express them in a language-neutral manner. We would also have to decide whether MI belongs in the CLS and what this would mean for languages that don't want this concept (presumably VB.NET, for example). Of course, that's the business we are in as a common language runtime, but we haven't got around to doing it for MI yet. The number of places where MI is truly appropriate is actually quite small. In many cases, multiple interface inheritance can get the job done instead. In other cases, you may be able to use encapsulation and delegation. If we were to add a slightly different construct, like mixins, would that actually be more powerful? Multiple implementation inheritance injects a lot of complexity into the implementation. This complexity impacts casting, layout, dispatch, field access, serialization, identity comparisons, verifiability, reflection, generics, and probably lots of other places. Guess it would be clear..

Daril · Answer

Multiple inheritance brings more complexity Interfaces are abstract classes that help us to properly hold its inner working of a program from being publicly accessible. It improves reusability It is not possible to attain multiple inheritances through extends keyword. Consider this example Class Cartoon cant extends class Anime and Manga. And also, in the cart.view() part it confuses which to call. Like whether to call the method of class Anime or the method of class Manga. But using implements keyword in inheritance, Multiple inheritance is possible. (Anime)cart.view(); - calls class Anime’s view (Manga)cart.view(); - calls class Manga’s view..

Pankaj Kumar Choudhary · Answer

.Net doesn't support multiple inheritance due to the problem of diamond problem.

Upendra Pratap Shahi · Answer

C# and Java languages don't support multiple inheritance because of the diamond problem [ ^ ]. Here is the short summary: The diamond problem is an ambiguity that arises when two classes B and C inherit from A, and class D inherits from both B and C. If a method in D calls a method defined in A (and does not override the method), and B and C have overridden that method differently, then from which class does it inherit: B, or C? Go through below link-- WHy C#net doesnot support Mul.inheritance? [ ^ ] http://www.wbcsoftwarelab.com/Forum/index.php?topic=266.0 [ ^ ] http://www.dotnetspider.com/forum/147250-Why-.Net-does-not-support-Multiple-Inheritance.aspx [ ^ ]

Goutomi Chatterjee · Answer

Even if you change the method name multiple inheriatance will not work. Intellisense will itself not provide the method name. It will give only one method name

Joginder Banger · Answer

but sathish kumar is one more thing add in question, this type of problem we can remove with the help of interface. but same condition are occur when two interface inheritance in one single class. What can solve this type of problem.

Jignesh Trivedi · Answer

hi, C# as well as Java languages don't support multiple inheritance because of the diamond problem. to know more about diamond proble please refer http://en.wikipedia.org/wiki/Diamond_problem#The_diamond_problem Also refer... http://blogs.msdn.com/b/csharpfaq/archive/2004/03/07/85562.aspx hope this will help you

Basheer Ahamed · Answer

Hi Sathishkumar The above method is good but instead of same method ( public void CalculateArea() ) in both class if i place different method, will it work, If now then why. Thanks in advance Regards Basheer