Inheritance

Question

I have a doubt in Inheritance 1I have a common class named - common It has 3 child classes child1child2child3 2 I have a common class named - state It has 3 child classes state1 state2 state3 I have a function named xyz() in all the 3 childclasses of common which I want to move to the parent class common. The function xyz( ) in child1 uses state1 class inside the function creates object for state1 class. The function xyz( ) in child2 uses state2 class and creates object for state2 class. The function xyz( ) in child3 uses state3 class and creates object for state3 class. But the procedure is same in all the function xyz()of the 3 childclasses the only difference is usage of classes state1 state2 state3. In this case how can I put that xyz()function in parent class.so that all the 3 child classes can access the function from the parent class... Is it necessary that I have to use Generic Inheritance.... could anybody throw some light on it?

keerthi · Answer

Passing the baseclass state in place of state1 state2 state3 does not work as the child classes contain additionaly required variables not present in state.

Alan · Answer

The only way of doing this that I can think of is as follows: using System; class Test { static void Main() { child1 c1 = new child1(); state1 s1 = (state1)c1.xyz(); child2 c2 = new child2(); state2 s2 = (state2)c2.xyz(); child3 c3 = new child3(); state3 s3 = (state3)c3.xyz(); } } class common { public state xyz() { state s = null; if (this is child1) s = new state1(); else if (this is child2) s = new state2(); else if (this is child3) s = new state3(); return s; } } class child1: common {} class child2: common {} class child3: common {} class state { } class state1 : state { public state1() { Console.WriteLine(state1); } } class state2 : state { public state2() { Console.WriteLine(state2); } } class state3 : state { public state3() { Console.WriteLine(state3); } } /* the output is: state1 state2 state3 */ /* the output is: state1 state2 state3 */ However it's hardly good OO practice for a base class to assume knowledge of its child classes so I can't really recommend it unless you must do it this way for some reason.

Mike Gold · Answer

I have a doubt in Inheritance 1I have a common class named - common It has 3 child classes child1child2child3 2 I have a common class named - state It has 3 child classes state1 state2 state3 I have a function named xyz() in all the 3 childclasses of common which I want to move to the parent class common. The function xyz( ) in child1 uses state1 class inside the function creates object for state1 class. The function xyz( ) in child2 uses state2 class and creates object for state2 class. The function xyz( ) in child3 uses state3 class and creates object for state3 class. But the procedure is same in all the function xyz()of the 3 childclasses the only difference is usage of classes state1 state2 state3. In this case how can I put that xyz()function in parent class.so that all the 3 child classes can access the function from the parent class... Is it necessary that I have to use Generic Inheritance.... could anybody throw some light on it? just create a virtual function in state called DoStateSpecific. Overridde it in all three state classes. Move xyz to the child base class and declare a member in the child base class state _state; or you can pass the state into xyz xyz(state myState) // myState can be of type state1 state2 state3 do the state specific stuff inside of the DoStateSpecific override function.