The purpose of delegates [duplicate]

Answer 1

As you noted a delegate is a way to create a signature for an method call. There are many great examples of using delegates, but the one that really opened my mind is this example.

public delegate Duck GetDuckDelegate();

public GetDuckDelegate GiveMeTheDuckFactoryMethod(string type)
{
  switch(type)
  {
    case "Rubber":
      return new GetDuckDelegate(CreateRubberDuck);
    case "Mallard":
      return new GetDuckDelegate(CreateMallardDuck);
    default:
      return new GetDuckDelegate(CreateDefaultDuck);
  }
}

public Duck CreateRubberDuck()
{
  return new RubberDuck();
}

public Duck CreateMallardDuck()
{
  return new MallardDuck();
}

public Duck CreateDefaultDuck()
{
  return new Duck();
}

Then to use it

public static void Main() {
  var getDuck = GiveMeTheDuckFactoryMethod("Rubber");
  var duck = getDuck();
}

Arguably, the Factory pattern would be a better method for this, but I just thought up this example on the fly and thought it proved the point of how delegates can be treated as objects