- [ctype_alnum](/functions/ctype_alnum) - [ctype_alpha](/functions/ctype_alpha) - [ctype_cntrl](/functions/ctype_cntrl) - [ctype_digit](/functions/ctype_digit) - [ctype_graph](/functions/ctype_graph) - [ctype_lower](/functions/ctype_lower) - [ctype_print](/functions/ctype_print) - [ctype_punct](/functions/ctype_punct) - [ctype_space](/functions/ctype_space) - [ctype_upper](/functions/ctype_upper) - [ctype_xdigit](/functions/ctype_xdigit)