c# - Declaring a variable inside or outside an foreach loop: which is faster/better?

Question

Which one of these is the faster/better one?

This one:

List<User> list = new List<User>();
User u;

foreach (string s in l)
{
    u = new User();
    u.Name = s;
    list.Add(u);
}

Or this one:

List<User> list = new List<User>();

foreach (string s in l)
{
    User u = new User();
    u.Name = s;
    list.Add(u);
}

My newbie-developing skills tells me the first one is better, but a friend of mine tells me im wrong, but could not give me a good reason why the second one is better.

Is there any difference in performance at all?

Answer 1

Performance-wise both examples are compiled to the same IL, so there's no difference.

The second is better, because it more clearly expresses your intent if u is only used inside the loop.