String.GetEnumerator Method

using System;

class Example
{
   public static void Main() 
   {
      EnumerateAndDisplay("Test Case");
      EnumerateAndDisplay("This is a sentence.");
      EnumerateAndDisplay("Has\ttwo\ttabs" );
      EnumerateAndDisplay("Two\nnew\nlines");
   }

   static void EnumerateAndDisplay(String phrase)
   {
      Console.WriteLine("The characters in the string \"{0}\" are:",
                        phrase);

      int CharCount = 0;
      int controlChars = 0;
      int alphanumeric = 0;
      int punctuation = 0;

      foreach (var ch in phrase) {
         Console.Write("'{0}' ", ! Char.IsControl(ch) ? ch.ToString() : 
                                     "0x" + Convert.ToUInt16(ch).ToString("X4"));
         if (Char.IsLetterOrDigit(ch)) 
            alphanumeric++;
         else if (Char.IsControl(ch)) 
            controlChars++;
         else if (Char.IsPunctuation(ch)) 
            punctuation++;             
         CharCount++;
      }

      Console.WriteLine("\n   Total characters:        {0,3}", CharCount);
      Console.WriteLine("   Alphanumeric characters: {0,3}", alphanumeric);
      Console.WriteLine("   Punctuation characters:  {0,3}", punctuation);
      Console.WriteLine("   Control Characters:      {0,3}\n", controlChars);
   }
}
// The example displays the following output: 
//    The characters in the string "Test Case" are:
//    'T' 'e' 's' 't' ' ' 'C' 'a' 's' 'e' 
//       Total characters:          9 
//       Alphanumeric characters:   8 
//       Punctuation characters:    0 
//       Control Characters:        0 
//     
//    The characters in the string "This is a sentence." are:
//    'T' 'h' 'i' 's' ' ' 'i' 's' ' ' 'a' ' ' 's' 'e' 'n' 't' 'e' 'n' 'c' 'e' '.' 
//       Total characters:         19 
//       Alphanumeric characters:  15 
//       Punctuation characters:    1 
//       Control Characters:        0 
//     
//    The characters in the string "Has       two     tabs" are:
//    'H' 'a' 's' '0x0009' 't' 'w' 'o' '0x0009' 't' 'a' 'b' 's' 
//       Total characters:         12 
//       Alphanumeric characters:  10 
//       Punctuation characters:    0 
//       Control Characters:        2 
//     
//    The characters in the string "Two 
//    new 
//    lines" are: 
//    'T' 'w' 'o' '0x000A' 'n' 'e' 'w' '0x000A' 'l' 'i' 'n' 'e' 's' 
//       Total characters:         13 
//       Alphanumeric characters:  11 
//       Punctuation characters:    0 
//       Control Characters:        2