strcmp
strcoll()'s behavior is sometimes a little bit confusing. It depends on LC_COLLATE in your locale.
<?php
$a = 'a';
$b = 'A';
print strcmp ($a, $b) . "\n"; // prints 1
setlocale (LC_COLLATE, 'C');
print "C: " . strcoll ($a, $b) . "\n"; // prints 1
setlocale (LC_COLLATE, 'de_DE');
print "de_DE: " . strcoll ($a, $b) . "\n"; // prints -2
setlocale (LC_COLLATE, 'de_CH');
print "de_CH: " . strcoll ($a, $b) . "\n"; // prints -2
setlocale (LC_COLLATE, 'en_US');
print "en_US: " . strcoll ($a, $b) . "\n"; // prints -2
?>
This is useful e. g. if want to sort an array by using strcoll:
<?php
$a = array ('a', 'A', '', '', 'b', 'B');
setlocale (LC_COLLATE, 'C');
usort ($a, 'strcoll');
print_r ($a);
?>
This is like sort($a):
Array
(
[0] => A
[1] => B
[2] => a
[3] => b
[4] =>
[5] =>
)
<?php
setlocale (LC_COLLATE, 'de_DE');
usort ($a, 'strcoll');
print_r ($a)
?>
This is completely different:
Array
(
[0] => a
[1] => A
[2] =>
[3] =>
[4] => b
[5] => B
)
strcoll
(PHP 4 >= 4.0.5, PHP 5)
strcoll — 로케일 기반 문자열 비교
설명
int strcoll
( string $str1
, string $str2
)
str1 이 str2 보다 작으면 < 0를; str1 이 str2 보다 크면 > 0를, 동일하면 0을 반환합니다. strcoll()은 비교에 현재 로케일을 사용합니다. 현재 로케일이 C나 POSIX이면, 이 함수는 strcmp()와 동일합니다.
이 비교는 대소문자를 구별하며, strcmp()와는 다르게 바이너리 호환이 아닙니다.
Note: strcoll()은 PHP 4.0.5에서 추가되었지만, win32에서는 4.2.3까지 사용할 수 없었습니다.
참고: ereg(), strcmp(), strcasecmp(), substr(), stristr(), strncasecmp(), strncmp(), strstr(), setlocale().
add a note
User Contributed Notesstrcoll
sakkarinlaohawisut15 at hotmail dot com
22-Mar-2003 11:31
22-Mar-2003 11:31
27-Aug-2002 07:05
Note that some platforms implement strcmp() and strcasecmp() according to the current locale when strings are not binary equal, so that strcmp() and strcoll() will return the same value! This depends on how the PHP strcmp() function is compiled (i.e. if it uses the platform specific strcmp() found in its standard library!).
In that case, the only difference between strcoll() and strcmp() is that strcoll() may return 0 for distinct strings(i.e. consider strings are equal) while strcmp() will differentiate them if they have distinct binary encoding! This typically occurs on Asian systems.
What you can be sure is that strcmp() will always differentiate strings that are encoded differently, but the relative order may still use the current locale setting for collation order!