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strcoll

(PHP 4 >= 4.0.5, PHP 5, PHP 7, PHP 8)

strcollComparación de strings localizadas

Descripción

strcoll(string $string1, string $string2): int

Se debe tener en cuenta que esta comparación distingue entre mayúsculas y minúsculas, y que, a diferencia de strcmp(), no es compatible con strings binarios.

strcoll() utiliza la configuración local/regional actual para realizar la comparación. Si la configuración local/regional actual es C o POSIX, esta función es entonces equivalente a la función strcmp().

Parámetros

string1

El primer string.

string2

El segundo string.

Valores devueltos

Devuelve < 0 si string1 es menor que string2; > 0 si string1 es mayor que string2, y 0 si los dos strings son iguales.

Ver también

  • preg_match() - Realiza una búsqueda de coincidencia con una expresión regular estándar
  • strcmp() - Comparación binaria de strings
  • strcasecmp() - Comparación insensible a mayúsculas/minúsculas de strings binarios
  • substr() - Devuelve un segmento de string
  • stristr() - Versión insensible a mayúsculas y minúsculas de strstr
  • strncasecmp() - Comparación binaria de strings insensible a mayúsculas/minúsculas
  • strncmp() - Comparación binaria de los n primeros caracteres
  • strstr() - Encuentra la primera ocurrencia en un string
  • setlocale() - Modifica la información de configuración local

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User Contributed Notes 3 notes

up
9
Anonymous
22 years ago
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!
up
7
mkroese at eljakim dot nl
5 years ago
You should not rely on this function to properly compare localized strings.

<?php
$a
= "Österreich";
$b = "Oesterreich";
$z = "Zeta";

echo
setlocale(LC_ALL, 0) . PHP_EOL; // (on my mac: C/en_US.UTF-8/C/C/C/C)
echo strcoll($a, $b) . PHP_EOL; // 116
echo strcoll($b, $a) . PHP_EOL; // -116
echo strcoll($a, $z) . PHP_EOL; // 105

echo setlocale(LC_ALL, "de_DE") . PHP_EOL; // de_DE
echo strcoll($a, $b) . PHP_EOL; // 135
echo strcoll($b, $a) . PHP_EOL; // -135
echo strcoll($a, $z) . PHP_EOL; // 124

$collator = new Collator("de_DE");
echo
$collator->compare($a, $b); // 1
echo $collator->compare($b, $a); // -1
echo $collator->compare($a, $z); // -1
?>

Using the Collator (from the intl module) you will get the expected result for e.g. sorting such that the string "Österreich" will rank higher than "Zeta", but after "Oesterreich".

strcoll's output will differ per platform, locale and used c library, while the Collator will give more stable results on different platforms.
up
-1
sakkarinlaohawisut15 at hotmail dot com
22 years ago
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
)
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