Question

I’m really blanking out here.

I’m wondering why I can’t declare a delegate type within a method, but rather I have to do it at a class level.

namespace delegate_learning
{
    class Program
    {
        // Works fine
        public delegate void anon_delgate(int i);

        static void Main(string[] args)
        {
            HaveFun();
            Console.Read();
        }

        public static void HaveFun()
        {
            // Throws an error :/
            //delegate void anon_delgate(int i);

            anon_delgate ad = delegate(int i) { Console.WriteLine(i.ToString());};
        }


    }
}

Edit: I’m researching Lambda Expressions and backing up into how it was before Lambdas, for my own personal knowledge.

Answer 1

// Throws an error :/
delegate void anon_delgate(int i);

It throws an error, because it’s a type definition, not a variable declaration. Any type definition is not allowed inside method. It’s allowed only at class scope, or namespace scope.

namespace A
{
   delegate void X(int i); //allowed
   public class B
   {
         delegate void Y(int i); //also allowed
   }
}

---

By the way, why don’t you write this:

anon_delgate ad = i => Console.WriteLine(i.ToString());

It’s called lambda expression.