C#: Why can't we have inner methods?

Question

Very often it happens that I have private methods which become very big and contain repeating tasks but these tasks are so specific that it doesn't make sense to make them available to any other code part.

So it would be really great to be able to create 'inner methods' in this case.

Is there any technical (or even phylosophical?) limitation that prevents C# from giving us this? Or did I miss something?

Answer 1

Well, we can have "anonymous methods" defined inside a function (I don't suggest using them to organize a large method):

void test() {
   Action t = () => Console.WriteLine("hello world");  // C# 3.0+
   // Action t = delegate { Console.WriteLine("hello world"); }; // C# 2.0+
   t();
}

Answer 2

If something is long and complicated than usually its good practise to refactor it to a separate class (either normal or static - depending on context) - there you can have private methods which will be specific for this functionality only.

Answer 3

I know a lot of people dont like regions but this is a case where they could prove useful by grouping your specific methods into a region.

Answer 4

If your method becomes too big, consider putting it in a separate class, or to create private helper methods. Generally I create a new method whenever I would normally have written a comment.

Answer 5

Could you give a more concrete example? After reading your post I have the following impression, which is of course only a guess, due to limited informations:

• Private methods are not available outside your class, so they are hidden from any other code anyway.
• If you want to hide private methods from other code in the same class, your class might be to big and might violate the single responsibility rule.
• Have a look at anonymous delegates an lambda expressions. It's not exactly what you asked for, but they might solve most of your problems.

Achim

Answer 6

The better solution is to refactor this method to separate class. Create instance of this class as private field in your initial class. Make the big method public and refactor big method into several private methods, so it will be much clear what it does.