foreach over a list of strings in C#

Question

I would like to do something like the following in C#, but I can't figure out how to instantiate any of the container types in place:

foreach (string aOrB in new Tuple("A","B"))
{
    fileNames.Add("file" + aOrB + ".png");
}

I know the typical way it to create the Tuple/Array/Set container in the surrounding scope. Is there something better?

So do you need `List` of strings or `Tuple`? It is two pretty different data structures. — Andrey Korneyev, Jan 21 '16 at 14:24
Do you mean `new List{"A", "B"}`? Or is it a challenge to iterate [over properties](http://stackoverflow.com/q/957783/1997232)? — Sinatr, Jan 21 '16 at 14:24
Or you can also go with just an array. `in new[] {"A", "B"}` — krillgar, Jan 21 '16 at 14:25

score 12 · Answer 1 · answered Jan 21 '16 at 14:25

As far as I understand, you want to provide a set of items defined ad-hoc for your loop. You can do this with the array initialization syntax:

foreach (string aOrB in new[] { "A", "B" })
{
    fileNames.Add("file" + aOrB + ".png");
}

This is already a shortened form of

foreach (string aOrB in new string[] { "A", "B" })
{
    fileNames.Add("file" + aOrB + ".png");
}

(the long form would be necessary if the compiler could not figure out the array element type from the elements)

score 1 · Answer 2 · answered Jan 21 '16 at 14:28

1

You can try the following:

foreach(string aOrB in new List<string>() { "a", "b" })
{
    fileNames.Add("file" + aOrB + ".png");
}

answered Jan 21 '16 at 14:28

Chris Wohlert

2 Answers2