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Char.IsControl Method (String, Int32)

Indicates whether the character at the specified position in a specified string is categorized as a control character.

Namespace:  System
Assembly:  mscorlib (in mscorlib.dll)

public static bool IsControl(
	string s,
	int index
)

Parameters

s
Type: System.String

A string.

index
Type: System.Int32

The position of the character to evaluate in s.

Return Value

Type: System.Boolean
true if the character at position index in s is a control character; otherwise, false.

ExceptionCondition
ArgumentNullException

s is null.

ArgumentOutOfRangeException

index is less than zero or greater than the last position in s.

Character positions in a string are indexed starting from zero.

Control characters are formatting and other non-printing characters, such as ACK, BEL, CR, FF, LF, and VT. The Unicode standard assigns code points from \U0000 to \U001F, \U007F, and from \U0080 to \U009F to control characters. According to the Unicode standard, these values are to be interpreted as control characters unless their use is otherwise defined by an application. Valid control characters are members of the UnicodeCategory.Control category.

The following example enumerates the characters in a string and determines whether any are control characters.

using System;

public class ControlChar
{
   public static void Main()
   {
      string sentence = "This is a " + Environment.NewLine + "two-line sentence.";
      for (int ctr = 0; ctr < sentence.Length; ctr++)
      {
         if (Char.IsControl(sentence, ctr))
           Console.WriteLine("Control character \\U{0} found in position {1}.", 
             Convert.ToInt32(sentence[ctr]).ToString("X4"), ctr);

      }
   }
}
// The example displays the following output to the console: 
//       Control character \U000D found in position 10. 
//       Control character \U000A found in position 11.

.NET Framework

Supported in: 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

.NET for Windows Store apps

Supported in: Windows 8

.NET for Windows Phone apps

Supported in: Windows Phone 8.1, Windows Phone Silverlight 8.1, Windows Phone Silverlight 8

Windows Phone 8.1, Windows Phone 8, Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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