String.GetEnumerator Method

Definition

Retrieves an object that can iterate through the individual characters in this string.

public CharEnumerator GetEnumerator ();

Returns

An enumerator object.

Examples

The following example iterates the characters in several strings and displays information about their individual characters. It uses the language iteration construct rather than a call to the 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(Char.IsControl(ch) ? $"{ch}" : $"0x{(ushort)ch: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

Remarks

Tip

Rather than calling the GetEnumerator method to retrieve a CharEnumerator object that you then use to enumerate a string, you should instead use your language's iteration construct (in C#, in F#, in C++/CLR, and in Visual Basic). foreach in C#, for..in in F#, for each in C++/CLR, and For Each in Visual Basic).

This method enables you to iterate the individual characters in a string. For example, the Visual Basic For Each, the F# for..in expression, and C# foreach statements invoke this method to return a CharEnumerator object that can provide read-only access to the characters in this string instance.

Applies to

Produkt Verze
.NET Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9
.NET Framework 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1
.NET Standard 2.0, 2.1

See also