C# ICollection get single value

var foo = myICollection.OfType<YourType>().FirstOrDefault();
    // or use a query
    var bar = (from x in myICollection.OfType<YourType>() where x.SomeProperty = someValue select x)
       .FirstOrDefault();

foreach(object o in collection) {
  return o;
}

IEnumerator en = collection.GetEnumerator();
en.MoveNext();
return en.Current;

IList iList = collection as IList;
if (iList != null) {
  // Implements IList, so can use indexer
  return iList[0];
}
// Use the slower way
foreach (object o in collection) {
  return o;
}

List<string> l = new List<string>();
l.Add("astring");

ICollection col1 = (ICollection)l;
ICollection<string> col2 = (ICollection<string>)l;

//example 1
IEnumerator e1 = col1.GetEnumerator();
if (e1.MoveNext())
    Console.WriteLine(e1.Current);

//example 2
if (col2.Count != 0)
    Console.WriteLine(col2.Single());