XVI. Character type functions

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".

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.

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

Requirements

None besides functions from the standard C library which are always available.

Installation

Beginning with PHP 4.2.0 these functions are enabled by default. For older versions you have to configure and compile PHP with --enable-ctype.

Runtime Configuration

This extension does not define any configuration directives.

Resource Types

This extension does not define any resource types.

Predefined Constants

This extension does not define any constants.

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_graph -- Check for any printable character(s) except space
ctype_lower -- Check for lowercase character(s)
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