C#统计输入的字符类型数量

using System;

namespace huangyibiao
{
    class Program
    {
        static void Main(string[] args)
        {
            int iCountLetters = 0;   //number of letters
            int iCountDigits = 0;    //number of digits
            int iCountPunctuations = 0; //number of punctuations

            Console.Write("Please enter a string to count: ");
            string strInput = Console.ReadLine();

            foreach (var chr in strInput)
            {
                if (char.IsLetter(chr))
                {
                    iCountLetters++;
                }
                else if (char.IsDigit(chr))
                {
                    iCountDigits++;
                }
                else if (char.IsPunctuation(chr))
                {
                    iCountPunctuations++;
                }
            }
            Console.WriteLine("There {0} letters, {1} digits and {2} punctuations.", iCountLetters, iCountDigits, iCountPunctuations);
        }
    }
}