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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 non-printing and formatting characters, such as ACK, BEL, CR, FF, LF, and VT. The Unicode standard assigns the following UTF-16 code units to control characters: from \U0000 to \U001F, \U007F, and from \U0080 to \U009F. 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, 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

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

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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