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XVII. Character Type Functions
Úvod
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.
Požadavky
None besides functions from the standard C library which are always available.
Instalace
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.
Verze PHP pro Windows má vestavěnou podporu pro toto rozšíření. K použití těchto funkcí není třeba načítat žádná další rozšíření.
Poznámka: Builtin support for ctype is available with PHP 4.3.0.
Konfigurace běhu
Toto rozšíření nemá definováno žádné konfigurační direktivy.
Typy prostředků
Toto rozšíření nemá definován žádný typ prostředku (resource).
Předdefinované konstanty
Toto rozšíření nemá definovány žádné konstanty.
- Obsah
- 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
| Předcházející | Domů | Další |
| crack_opendict | Nahoru |