Introduction
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. It means that if you pass an integer smaller than 256 it will use the ASCII value of it to see if it fits in the specified range (digits are in 0x30-0x39). If the number is between -128 and -1 inclusive then 256 will be added and the check will be done on that.
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. When called with an empty string
the result will always be TRUE
in PHP < 5.1 and FALSE
since 5.1.
Passing anything else but a string or integer will
return FALSE
immediately.
It should be noted that ctype functions are always preferred over regular expressions, and even to some equivalent "str_*" and "is_*" functions. This is because of the fact that ctype uses a native C library and thus processes significantly faster.
Note:
These functions are not related to the Python "ctypes" library at all. The extension name stems from the ctype.h C header file that their C equivalents are defined in.
This extension also predates Python "ctypes" so any confusion caused by this naming is hardly our fault ...
English translation
You have asked to visit this site in English. For now, only the interface is translated, but not all the content yet.If you want to help me in translations, your contribution is welcome. All you need to do is register on the site, and send me a message asking me to add you to the group of translators, which will give you the opportunity to translate the pages you want. A link at the bottom of each translated page indicates that you are the translator, and has a link to your profile.
Thank you in advance.
Document created the 30/01/2003, last modified the 26/10/2018
Source of the printed document:https://www.gaudry.be/en/php-rf-intro.ctype.html
The infobrol is a personal site whose content is my sole responsibility. The text is available under CreativeCommons license (BY-NC-SA). More info on the terms of use and the author.
References
These references and links indicate documents consulted during the writing of this page, or which may provide additional information, but the authors of these sources can not be held responsible for the content of this page.
The author This site is solely responsible for the way in which the various concepts, and the freedoms that are taken with the reference works, are presented here. Remember that you must cross multiple source information to reduce the risk of errors.