Description: ZipCode structure that takes a zip code on the constructor and parses it to Zip & Zip+4 if it’s valid. Sets it to nothing otherwise

Link: http://www.codekeep.net/snippets/a630ce70-b87e-4cdf-9cd2-1013b5e48d48.aspx

truct ZipCode
        {
            private string m_Zip;
            public string Zip
            {
                get { return m_Zip; }
                set { m_Zip = value; }
            }

            private string m_Zip4;
            public string Zip4
            {
                get { return m_Zip4; }
                set { m_Zip4 = value; }
            }

            public override string ToString()
            {
                if (String.IsNullOrEmpty(Zip) || Zip.Length != 5) { return String.Empty; }
                if (String.IsNullOrEmpty(Zip4) || Zip4.Length != 4)
                {
                    return Zip;
                }
                else
                {
                    return Zip + "-" + Zip4;
                }
            }

            public ZipCode(string zip)
            {
                string regularExpression = "^(?<Zip>\\d{5})-{0,1}(?<Zip4>(\\d{4}){0,1})$";
                Regex reg = new Regex(regularExpression);
                Match match = reg.Match(zip);

                if (match != null && match.Success)
                {
                    m_Zip = match.Groups["Zip"].Value;
                    m_Zip4 = match.Groups["Zip4"].Value;
                }
                else
                {
                    m_Zip = String.Empty;
                    m_Zip4 = String.Empty;
                }
            }
        }