asp.net - C#- Validation for US or Canadian zip code

Question

I am using following method to validate US or Canadian zip code, but i think it is not working fine for me. Please suggest me the changes in the regular expression.

private bool IsUSorCanadianZipCode(string zipCode)
    {
        bool isValidUsOrCanadianZip = false;
        string pattern = @"^d{5}-d{4}|d{5}|[A-Z]d[A-Z] d[A-Z]d$";
        Regex regex = new Regex(pattern);
        return isValidUsOrCanadianZip = regex.IsMatch(zipCode);
    }

Thanks.

Answer 1

    var _usZipRegEx = @"^d{5}(?:[-s]d{4})?$";
    var _caZipRegEx = @"^([ABCEGHJKLMNPRSTVXY]d[ABCEGHJKLMNPRSTVWXYZ]) {0,1}(d[ABCEGHJKLMNPRSTVWXYZ]d)$";

    private bool IsUSOrCanadianZipCode(string zipCode)
    {
        var validZipCode = true;
        if ((!Regex.Match(zipCode, _usZipRegEx).Success) && (!Regex.Match(zipCode, _caZipRegEx).Success))
        {
            validZipCode = false;
        }
        return validZipCode;
    }
}