How to Check a Character Value in C

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