Aqueduct.Extensions.Inflector.AddOrdinalSuffix C# (CSharp) Method

        public static string AddOrdinalSuffix(this string number)
        {
            if (number.IsStringNumeric())
            {
                int n = int.Parse(number);
                int nMod100 = n % 100;

                if (nMod100 >= 11 && nMod100 <= 13)
                    return String.Concat(number, "th");

                switch (n % 10)
                {
                    case 1:
                        return String.Concat(number, "st");
                    case 2:
                        return String.Concat(number, "nd");
                    case 3:
                        return String.Concat(number, "rd");
                    default:
                        return String.Concat(number, "th");
                }
            }
            return number;
        }