Interface vs. Abstract classes

Interface vs. Abstract classes Abstract class needs to have at least one "pure virtual method" * In case of Interface all the methods should be "pure virtual" An Abstract class can have all methods as "pure virtual" and still it will not allow multiple inheritance... With Interface multiple inheritance is possible in .Net... Various access modifiers such as abstract, protected, internal, public, virtual, overrides etc are not useful in case of Interface but they are in case of Abstract classes Class implementing Interface has to implement all the methods of the Interface, this is not required in case of Abstract classes As Interface cannot be instantiated, they do not have constructors and destructors like the way Abstract classes can... Interface cannot contain a static method whereas an Abstract class can have... There are few more points which I can recollect but I think that this is enough for a tip... If anyone needs more info do write back to me... :-) * pure virtual method is a method which has just definition but not implementation... **************************************************************************** **************************************************************************** ******************************************* An addition to yesterday's tip... We cannot access static member of a class using object of a class in C#, though this is possible in VB.Net... Thanks to Jacob Cynamon, MS & Kathleen Dollard, MVP for quickly reminding the same... Thanks all for sending a wonderful queries & feedbacks and making my evenings more useful... **************************************************************************** **************************************************************************** ******************************************* PS: Many of us work on weekends, I don't think (current thought!!) that its a good practice doing that, at least if you are being gauged on the basis of your willingness to work on weekends then its surely very bad... I am trying to start a movement to abolish this social evil of working on weekends, so no tips on weekends...:-) BONUS TIP: Spend time with your family this weekend... :-)