My first extension method, could it be written better?

Question

Because this is my first attempt at an extension method that seems quite useful to me, I just want to make sure I'm going down the right route

 public static bool EqualsAny(this string s, string[] tokens, StringComparison comparisonType)
    {
        foreach (string token in tokens)
        {
            if (s.Equals(token, comparisonType))
            {
                return true;
            }
        }

        return false;
    }

Called by

if (queryString["secure"].EqualsAny(new string[] {"true","1"}, StringComparison.InvariantCultureIgnoreCase))
{
    parameters.Protocol = Protocol.https;
}

EDIT: Some excellent suggestions coming through, exactly the sort of thing I was looking for. Thanks

EDIT:

I have decided on the following implementation

public static bool EqualsAny(this string s, StringComparison comparisonType, params string[] tokens)
{
    // for the scenario it is more suitable for the code to continue
    if (s == null) return false;

    return tokens.Any(x => s.Equals(x, comparisonType));
}

public static bool EqualsAny(this string s, params string[] tokens)
{
    return EqualsAny(s, StringComparison.OrdinalIgnoreCase, tokens);
}

I preferred using params over IEnumerable because it simplified the calling code

if (queryString["secure"].EqualsAny("true","1"))
{
    parameters.Protocol = Protocol.https;
}

A far cry on the previous

if (queryString["secure"] != null)
{
    if (queryString["secure"] == "true" || queryString["secure"] == "1")
    {
        parameters.Protocal = Protocal.https;
    }
}

Thank you again!

Answer 1

Yes! First, you need to check s for null. Also, let it accept any IEnumerable<string> for tokens rather than just an array, and then use other linq operators to do the check:

public static bool EqualsAny(this string s, IEnumerable<string> tokens, StringComparison comparisonType)
{
    if (s== null) return false;
    return tokens.Any(t => s.Equals(t, comparisonType));
}

---

Thinking about how to handle a null value for s, there's a third option no one's used yet:

 public static bool EqualsAny(this string s, IEnumerable<string> tokens, StringComparison comparisonType)
{
    if (s== null) return tokens.Any(t => t == null);
    return tokens.Any(t => s.Equals(t, comparisonType));
}

---

Finally, regarding your chosen implementation: if you're going to have overloads, you might as well have IEnumerable overloads as well, and have your params code call those.