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:

  1. isalnum(): Checks if a character is alphanumeric.
  2. isalpha(): Checks if a character is alphabetic.
  3. iscntrl(): Checks if a character is a control character.
  4. isdigit(): Checks if a character is a digit.
  5. isgraph(): Checks if a character is a printable ASCII character (excluding space).
  6. islower(): Checks if a character is lowercase.
  7. isprint(): Checks if a character is a printable ASCII character.
  8. ispunct(): Checks if a character is a punctuation character (printable char excluding space and alphanumeric).
  9. isspace(): Checks if a character is a whitespace character.
  10. isupper(): Checks if a character is uppercase.
  11. 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