How to make the class as an IEnumerable in C#?

Question

So I've got a class and a generic List inside of it, but it is private.

class Contacts {     List<Contact> contacts;     ... } 

I want to make the class work as this would do:

foreach(Contact in contacts) .... ; 

like this (not working):

Contacts c; foreach(Contact in c) .... ; 

In the example above the Contact class instance c has to yield return every item from contacts(private member of c)

How do I do it? I know it has to be IEnumerable with yield return, but where to declare that?

Answer 1

Implement the interface IEnumerable:

class Contacts : IEnumerable<Contact> {     List<Contact> contacts;      #region Implementation of IEnumerable     public IEnumerator<Contact> GetEnumerator()     {         return contacts.GetEnumerator();     }      IEnumerator IEnumerable.GetEnumerator()     {         return GetEnumerator();     }     #endregion }