XIV. Character type functions


This module is EXPERIMENTAL. That means, that the behaviour of these functions, these function names, in concreto ANYTHING documented here can change in a future release of PHP WITHOUT NOTICE. Be warned, and use this module at your own risk.

These functions check whether a character or string falls into a certain character class according to the current locale.

When called with an integer argument these functions behave exactly like their C counterparts.

When called with a string argument they will check every character in the string and will only return TRUE if every character in the string matches the requested criteria.

Passing anything else but a string or integer will return FALSE immediately.


These functions are new as of PHP 4.0.4 and might change their name in the near future. Suggestions are to change them to ctype_issomething() instead of ctype_something() or even to make them part of ext/standard and use their original C-names, although this would possibly lead to further confusion regarding the isset() vs. is_sometype() problem.

Table of Contents
ctype_alnum -- Check for alphanumeric character(s)
ctype_alpha -- Check for alphabetic character(s)
ctype_cntrl -- Check for control character(s)
ctype_digit -- Check for numeric character(s)
ctype_lower -- Check for lowercase character(s)
ctype_graph -- Check for any printable character(s) except space
ctype_print -- Check for printable character(s)
ctype_punct --  Check for any printable character which is not whitespace or an alphanumeric character
ctype_space -- Check for whitespace character(s)
ctype_upper -- Check for uppercase character(s)
ctype_xdigit --  Check for character(s) representing a hexadecimal digit