Question

Is there a LINQ function for this is or would one have to code it themselves like this:

static string GetLongestStringInList()
{
    string longest = list[0];

    foreach (string s in list)
    {
        if (s.Length > longest.Length)
        {
            longest = s;
        }
    }

    return longest;
}

Answer 1

This will do it with only one loop iteration:

list.Aggregate("", (max, cur) => max.Length > cur.Length ? max : cur);