Question

I want to do something like this

public class Class1
    {
       public Class1()
       {

       }
       public Class1(int a)
       {

       }
    }
   public class Class2 :Class1
    {
       public Class2(int a)
       {

       }
       public Class2(): base(2)
       {
         this(2);   // new Class2(2);
       }

    }

I know this can’t be achieved in Java (can use one between (super or this) in the first line)

But somehow I am in need of this kind of work how to achieve that? Means calling the base class’s parameterised and derived class’s parameterised constructor in default constructor of derived class.

Answer 1

MSDN article on constructors is pretty good. Here are some relevant bits:

A constructor can use the base keyword
to call the constructor of a base
class.
….
A constructor can invoke another
constructor in the same object using
the this keyword. Like base, this can
be used with or without parameters,
and any parameters in the constructor
are available as parameters to this,
or as part of an expression.

This should work:

public class Class1
{
   public Class1()
   {

   }
   public Class1(int a)
   {

   }
}
public class Class2 :Class1
{
   public Class2(int a) : base(a)
   {

   }
   public Class2(): this(2)
   {
   }

}