isalnum | Check if a character is an alphabetic or a digit character |
isalpha | Check if a character is an alphabetic character |
iscntrl | Check if a character is a control character |
isdigit | Check if a character is a digit |
isgraph | Check if a character is a graphic character |
islower | Check if a character is a lowercase character |
isprint | Check if a character is a printable character |
ispunct | Check if a character is a punctuation character |
isspace | Check if a character is a space character |
isupper | Check if a character is an uppercase character |
isxdigit | Check if a character is an hexadecimal digit |
tolower | Convert a character to a lowercase character |
toupper | Convert a character to an uppercase character |