Where can I learn the ins and outs of enumerators in C#? [closed]

Question

Is there a good resource out there that explains the concept of enumerators and custom enumerators? Particularly one with a good solid example of why you would want to implement IEnumerable yourself and how you would use it effectively?

I occasionally come across yield and I am trying to get a better understanding of it.

Answer 1

The easiest example:

IEnumerable<string> GetNames()
{
  yield return "Bob";
  yield return "Bob's uncle";
  yield return "Alice";
  yield return "Stacy";
  yield return "Stacy's mom";
}

Usage:

foreach (var name in GetNames())
{
  Console.WriteLine(name);
}

To see it in action, place a debugger breakpoint on every line in the GetNames method.

Answer 2

Another book I found quite useful when I was learning about IEnumerable and IEnumerator is Troelsen's Pro C# 2008 book. It explains what the interfaces contain and how to build iterators with the "yield" keyword.

Hope this help.