C# extension methods for the Int class.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ExtensionOverflow
{
    /// <summary>
    /// Integer Extensions
    /// </summary>
    public static class IntExtensions
    {
        /// <summary>
        /// Get the ordinal value of positive integers.
        /// </summary>
        /// <remarks>
        /// Only works for english-based cultures.
        /// Code from: http://stackoverflow.com/questions/20156/is-there-a-quick-way-to-create-ordinals-in-c/31066#31066
        /// With help: http://www.wisegeek.com/what-is-an-ordinal-number.htm
        /// </remarks>
        /// <param name="number">The number.</param>
        /// <returns>Ordinal value of positive integers, or <see cref="int.ToString"/> if less than 1.</returns>
        public static string ToOrdinal(this int number)
        {
            const string TH = "th";
            string s = number.ToString();

            // Negative and zero have no ordinal representation
            if (number < 1)
            {
                return s;
            }

            number %= 100;
            if ((number >= 11) && (number <= 13))
            {
                return s + TH;
            }

            switch (number % 10)
            {
                case 1: return s + "st";
                case 2: return s + "nd";
                case 3: return s + "rd";
                default: return s + TH;
            }
        }

        #region PercentageOf calculations

        /// <summary>
        /// The numbers percentage
        /// </summary>
        /// <param name="number">The number.</param>
        /// <param name="percent">The percent.</param>
        /// <returns>The result</returns>
        public static decimal PercentageOf(this int number, int percent)
        {
            return (decimal)(number * percent / 100);
        }

        /// <summary>
        /// Percentage of the number.
        /// </summary>
        /// <param name="percent">The percent</param>
        /// <param name="number">The Number</param>
        /// <returns>The result</returns>
        public static decimal PercentOf(this int position, int total)
        {
            decimal result = 0;
            if (position > 0 && total > 0)
            {
                result = (decimal)position / (decimal)total * 100;
            }
            return result;
        }
        public static decimal PercentOf(this int? position, int total)
        {
            if (position == null)
            {
                return 0;
            }

            decimal result = 0;
            if (position > 0 && total > 0)
            {
                result = (decimal)((decimal)position / (decimal)total * 100);
            }
            return result;
        }

        /// <summary>
        /// The numbers percentage
        /// </summary>
        /// <param name="number">The number.</param>
        /// <param name="percent">The percent.</param>
        /// <returns>The result</returns>
        public static decimal PercentageOf(this int number, float percent)
        {
            return (decimal)(number * percent / 100);
        }

        /// <summary>
        /// Percentage of the number.
        /// </summary>
        /// <param name="percent">The percent</param>
        /// <param name="number">The Number</param>
        /// <returns>The result</returns>
        public static decimal PercentOf(this int position, float total)
        {
            decimal result = 0;
            if (position > 0 && total > 0)
            {
                result = (decimal)((decimal)position / (decimal)total * 100);
            }
            return result;
        }

        /// <summary>
        /// The numbers percentage
        /// </summary>
        /// <param name="number">The number.</param>
        /// <param name="percent">The percent.</param>
        /// <returns>The result</returns>
        public static decimal PercentageOf(this int number, double percent)
        {
            return (decimal)(number * percent / 100);
        }

        /// <summary>
        /// Percentage of the number.
        /// </summary>
        /// <param name="percent">The percent</param>
        /// <param name="number">The Number</param>
        /// <returns>The result</returns>
        public static decimal PercentOf(this int position, double total)
        {
            decimal result = 0;
            if (position > 0 && total > 0)
            {
                result = (decimal)((decimal)position / (decimal)total * 100);
            }
            return result;
        }

        /// <summary>
        /// The numbers percentage
        /// </summary>
        /// <param name="number">The number.</param>
        /// <param name="percent">The percent.</param>
        /// <returns>The result</returns>
        public static decimal PercentageOf(this int number, decimal percent)
        {
            return (decimal)(number * percent / 100);
        }

        /// <summary>
        /// Percentage of the number.
        /// </summary>
        /// <param name="percent">The percent</param>
        /// <param name="number">The Number</param>
        /// <returns>The result</returns>
        public static decimal PercentOf(this int position, decimal total)
        {
            decimal result = 0;
            if (position > 0 && total > 0)
            {
                result = (decimal)position / (decimal)total * 100;
            }
            return result;
        }

        /// <summary>
        /// The numbers percentage
        /// </summary>
        /// <param name="number">The number.</param>
        /// <param name="percent">The percent.</param>
        /// <returns>The result</returns>
        public static decimal PercentageOf(this int number, long percent)
        {
            return (decimal)(number * percent / 100);
        }

        /// <summary>
        /// Percentage of the number.
        /// </summary>
        /// <param name="percent">The percent</param>
        /// <param name="number">The Number</param>
        /// <returns>The result</returns>
        public static decimal PercentOf(this int position, long total)
        {
            decimal result = 0;
            if (position > 0 && total > 0)
            {
                result = (decimal)position / (decimal)total * 100;
            }
            return result;
        }

        #endregion

        public static string ToString(this int? value, string defaultvalue)
        {
            if (value == null)
            {
                return defaultvalue;
            }
            return value.Value.ToString();
        }

        public static bool IsInRange(this int self, int begin, int end)
        {
            return self >= begin && self <= end;
        }

    }
}