计算一个字符串中的数字，字母，标点数

//foreach循环

//int countLetters = 0;

//int countDigits = 0;

//int countPunctuations = 0;

//string input;

//Console.WriteLine("请输入一个字符串:");

//input = Console.ReadLine();

//foreach (char chr in input)

//{

// if (char.IsLetter(chr))

// countLetters++;

// if (char.IsDigit(chr))

// countDigits++;

// if (char.IsPunctuation(chr))

// countPunctuations++;

//}

//Console.WriteLine("字母的个数为：{0}",countLetters );

//Console.WriteLine("数字的个数为：{0}", countDigits);

//Console.WriteLine("标点符号的个数为：{0}", countPunctuations);

//Console.ReadLine();