Determine sequence contains no element using LINQ [duplicate]

Answer 1

Max() throws an ArgumentNullException if the source doesn't have any elements. You could write an extension method that checks for this and returns a null (or whatever you want) if there aren't any elements.

public static Nullable MaxOrNull(this IEnumerable source)
{
    if (source.Count() == 0)
        return null;
    else
        return source.Max();
}