iTextSharp.text.pdf.Barcode39.GetChecksum C# (CSharp) Метод

        internal static char GetChecksum(string text) {
            int chk = 0;
            for (int k = 0; k < text.Length; ++k) {
                int idx = CHARS.IndexOf(text[k]);
                if (idx < 0)
                    throw new ArgumentException("The character '" + text[k] + "' is illegal in code 39.");
                chk += idx;
            }
            return CHARS[chk % 43];
        }