Question

As an abstract class cannot be instantiated, why is a constructor still allowed inside the abstract class?

public abstract class SomeClass 
 {  
     private string _label;

     public SomeClass(string label)  
     {  
         _label=label;
     }  
}

Answer 1

Constructors of any derived class still have to call a constructor in the abstract class. If you don’t specify any constructors at all, all derived classes will just have to use the default parameterless one supplied by the compiler.

It absolutely makes sense to have a constructor – but “public” is really equivalent to “protected” in this case.