Compares strings using a language-aware "natural order" algorithm.

This method is a drop-in replacement for strnatcasecmp(). If the intl extension is available, strings are compared using a \Collator for the given language, so accented characters and other language-specific collation rules are taken into account. Numbers embedded in the strings are compared by their numeric value, as strnatcasecmp() does. If the intl extension is not available, or no language can be determined, this method falls back to strnatcasecmp().

Parameters

string $string1: The first string.

string $string2: The second string.

string|null $langcode: (optional) The language code to determine the collation rules. Defaults to the current language if the language manager service is available.

Return value

int Less than 0 if $string1 sorts before $string2, greater than 0 if $string1 sorts after $string2, and 0 if they are equal.

9 calls to NaturalSort::strnatcasecmp()

Action::sort in core/modules/system/src/Entity/Action.php

Block::sort in core/modules/block/src/Entity/Block.php

Sorts active blocks by weight; sorts inactive blocks by name.

ConfigEntityBase::sort in core/lib/Drupal/Core/Config/Entity/ConfigEntityBase.php

Callback for uasort() to sort configuration entities by weight and label.

DateFormat::sort in core/lib/Drupal/Core/Datetime/Entity/DateFormat.php

EntityDisplayModeBase::sort in core/lib/Drupal/Core/Entity/EntityDisplayModeBase.php

... See full list

File

core/lib/Drupal/Core/Utility/NaturalSort.php, line 42

Class

NaturalSort

Provides a language-aware replacement for strnatcasecmp().

Namespace

Drupal\Core\Utility

Code

public static function strnatcasecmp(string $string1, string $string2, ?string $langcode = NULL) : int {
  if (!extension_loaded('intl')) {
    return strnatcasecmp($string1, $string2);
  }
  if ($langcode === NULL && \Drupal::hasService('language_manager')) {
    $langcode = \Drupal::languageManager()->getCurrentLanguage()
      ->getId();
  }
  if ($langcode === NULL) {
    return strnatcasecmp($string1, $string2);
  }
  if (!isset(self::$collators[$langcode])) {
    $collator = \Collator::create($langcode);
    if ($collator === NULL) {
      return strnatcasecmp($string1, $string2);
    }
    // Compare numbers embedded in the strings by their numeric value, so
    // that for example "10" sorts after "9".
    $collator->setAttribute(\Collator::NUMERIC_COLLATION, \Collator::ON);
    self::$collators[$langcode] = $collator;
  }
  return self::$collators[$langcode]->compare($string1, $string2);
}

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