Question

I want to create a List like this :

List<int, DateTime> foo = new List<int, DateTime>();

but I get this error :

Using the generic type 'System.Collections.Generic.List<T>' requires 1 type arguments

Is it possible to do that in C# ?

Answer 1

It depends on what you want to do.

You can for example use a Dictionary if you want to use int as an index to access a DateTime like this:

Dictionary<int, DateTime> dict = new Dictionary<int, DateTime>();

dict.Add(1, DateTime.Now);
DateTime d = dict[1];

Or if you want to store an arbitrary list of values and allow duplicates you can use:

  var values = new List<Tuple<int, DateTime>>();
  values.Add(new Tuple<int, DateTime>(1, DateTime.Now));
  Tuple<int, DateTime> value = values.First();