Character type functions

&reftitle.intro; The functions provided by this extension check whether a character or string falls into a certain character class according to the current locale (see also setlocale). When called with an integer argument these functions behave exactly like their C counterparts from "ctype.h". 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.

&reftitle.required; None besides functions from the standard C library which are always available.

&reftitle.install; Beginning with PHP 4.2.0 these functions are enabled by default. For older versions you have to configure and compile PHP with .

&reftitle.runtime; &no.config;

&reftitle.resources; &no.resource;

&reftitle.constants; &no.constants;