C# | Char.IsControl(String, Int32) Method

This method is used to indicates whether the character at the specified position in a specified string is categorized as a control character.

Syntax:

public static bool IsControl (string s, int index);

Parameters:

s: It is the String. index: It is the character position in s.

Return Value: This method returns true if the character at position index in s is a control character otherwise it returns, false. 

Exceptions: 

• ArgumentNullException: If the s is null.
• ArgumentOutOfRangeException: If the index is less than zero or greater than the last position in s.

Note: Control characters are formatting and other non-printing characters, such as ACK, BEL, CR, FF, LF, and VT. 

Below programs illustrate the use of Char.IsControl(String, Int32) Method: 

Example 1: 

Example 2: For ArgumentNullException 

String '1234' does't contain control character at index 3
String 'psyc0lo' does't contain control character at index 4
Control character \U000A found in position 1.

s is null
Exception Thrown: System.ArgumentNullException

Example 3: For ArgumentOutOfRangeException 

String '1234' does't contain control character at index 3
String 'psyc0lo' does't contain control character at index 4
Control character \U000A found in position 1.

index is less than zero
Exception Thrown: System.ArgumentOutOfRangeException

Reference:

• https://learn.microsoft.com/en-us/dotnet/api/system.char.iscontrol?view=netframework-4.7.2#System_Char_IsControl_System_String_System_Int32_