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.

Answer 1

The US zipcode validation which works "on my machine" is

[RegularExpression(@"\d{5}$", ErrorMessage = "Invalid Zip Code")]

Answer 2

If you are using Data Annotation Validators, you can use a RegularExpression attribute like this:

[RegularExpression(@"(^\d{5}(-\d{4})?$)|(^[ABCEGHJKLMNPRSTVXYabceghjklmnprstvxy]{1}\d{1}[ABCEGHJKLMNPRSTVWXYZabceghjklmnprstv‌​xy]{1} *\d{1}[ABCEGHJKLMNPRSTVWXYZabceghjklmnprstvxy]{1}\d{1}$)", ErrorMessage = "That postal code is not a valid US or Canadian postal code.")]

(regex is from the link @huMptyduMpty posted above at http://geekswithblogs.net/MainaD/archive/2007/12/03/117321.aspx but my regex allows both upper and lower case letters)

Answer 3

    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;
    }
}