XV. Character Type Functions

Introdução

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 (inclusive) and 0 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.

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.

Dependências

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

Instalação

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. You can disable ctype support with --disable-ctype.

A versão para Windows do PHP tem suporte embutido para esta extensão. Você não precisa carregar nenhuma extensão adicional para utilizar essas funções.

Nota: Builtin support for ctype is available with PHP 4.3.0.

Configurações em execução

Esta extensão não define nenhum parâmetro de configuração no php.ini.

Tipos Resource

Esta extensão não possui nenhum tipo resource.

Constantes pré-definidas

Esta extensão não possui nenhuma constante.

Índice
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