In C programming, you can use the ctype.h
standard library to check the value of a char
type variable. There are several useful functions available for character value checks:
isalnum()
: Checks if a character is alphanumeric.isalpha()
: Checks if a character is alphabetic.iscntrl()
: Checks if a character is a control character.isdigit()
: Checks if a character is a digit.isgraph()
: Checks if a character is a printable ASCII character (excluding space).islower()
: Checks if a character is lowercase.isprint()
: Checks if a character is a printable ASCII character.ispunct()
: Checks if a character is a punctuation character (printable char excluding space and alphanumeric).isspace()
: Checks if a character is a whitespace character.isupper()
: Checks if a character is uppercase.isxdigit()
: Checks if a character is a hexadecimal digit (0-F).
The isspace()
function specifically checks for whitespace characters. Whitespace characters include:
- Horizontal tab (HT),
'\t'
(ASCII character 9) - Vertical tab (VT),
'\v'
(ASCII character 11) - Form Feed (FF),
'\f'
(ASCII character 12) - Carriage Return (CR),
'\r'
(ASCII character 13) - Space,
' '
(ASCII character 32) - New line,
'\n'
By using these functions, you can easily check and handle specific character values in your C programs.
Tags: C programming, character value, character checks, ctype.h