Question

I want to compare two strings and one of them may be a null string, am using StringComparison.InvariantCultureIgnoreCase feature of C#. This throws an exception in runtime when a null string is encountered. What shall I do to be able to compare even null strings?

Answer 1

As well as the options already given to you, you can consider using StringComparer.InvariantCultureIgnoreCase instead. StringComparer handles nulls without throwing exceptions:

using System;

class Test
{
    static void Main()
    {
        StringComparer comparer = StringComparer.InvariantCultureIgnoreCase;
        Console.WriteLine(comparer.Compare("a", "A"));
        Console.WriteLine(comparer.Compare("a", null));
        Console.WriteLine(comparer.Compare(null, "A"));
    }
}