array_combine - PHP code example

The php Function ArrayCombine

PHP offers a variety of array functions that help you manipulate and manage data structures. One of these is array_combine, which allows you to combine two arrays into one. It uses the elements from the first array as keys and the second array as values to create a new associative array. The function can be used to combine a wide range of data types.

Arrays in PHP are incredibly useful for storing multiple values at once. They can be manipulated to sort, search, and filter in various ways. However, when working with multiple arrays, it can be difficult to keep track of which value belongs to which key. The php function array_combine is an excellent solution to this problem, and it can be utilized in numerous applications.

This article will discuss the functionality, best practices, and potential challenges associated with the php function array_combine. It will also cover how to use the function in your code and some advanced tips to make it more efficient.

The php function array_combine takes in 2 arrays as input and returns an array with the keys from the first array as values and the values from the second array as the keys for the new array. Both arrays must have an equal number of elements in order to work correctly.

The main problem with this function is that it can produce incorrect results if you have duplicate keys in the keysets. This is because PHP (and nearly every other language) doesn’t store the object that corresponds to each key in memory; it only stores a unique hash that represents the key. When the array_combine function encounters a pair of keys that both produce the same hash, it simply moves on to the next value in the list.

array_combine example

            if (\is_string($v)) {
                $values[$k] = new static($v);
            } elseif (\is_array($v) && $values[$k] !== $v = static::wrap($v)) {
                $values[$k] = $v;
            }

            ++$i;
        }

        return null !== $keys ? array_combine($keys, $values) : $values;
    }

    /** * @param string|string[] $needle */
    public function after(string|iterable $needle, bool $includeNeedle = false, int $offset = 0): static
    {
        $str = clone $this;
        $i = \PHP_INT_MAX;

        if (\is_string($needle)) {

  protected function getViewsDisplayIDsWithRoute() {
    if (!isset($this->viewsDisplayPairs)) {
      $this->viewsDisplayPairs = [];

      // @todo Convert this method to some service.       $views = $this->getApplicableViews();
      foreach ($views as $data) {
        [$view_id, $display_id] = $data;
        $this->viewsDisplayPairs[] = $view_id . '.' . $display_id;
      }
      $this->viewsDisplayPairs = array_combine($this->viewsDisplayPairs, $this->viewsDisplayPairs);
    }
    return $this->viewsDisplayPairs;
  }

  /** * Returns a set of route objects. * * @return \Symfony\Component\Routing\RouteCollection * A route collection. */
  public function routes() {

// Get all enabled languages.     $translated_languages = $this->enabledLanguages;

    // Load all the content from any CSV files that exist for enabled languages.     foreach ($translated_languages as $language) {
      if (file_exists($default_content_path . "$language/$filename") &&
      ($handle = fopen($default_content_path . "$language/$filename", 'r')) !== FALSE) {
        $header = fgetcsv($handle);
        $line_counter = 0;
        while (($content = fgetcsv($handle)) !== FALSE) {
          $keyed_content[$language][$line_counter] = array_combine($header, $content);
          $line_counter++;
        }
        fclose($handle);
      }
      else {
        // Language directory exists, but the file in this language was not found,         // remove that language from list of languages to be translated.         $key = array_search($language, $translated_languages);
        unset($translated_languages[$key]);
      }
    }

$optimized_tokens = $this->optimizeTokens($context_tokens);
    // Iterate over cache contexts that have been optimized away and get their     // cacheability metadata.     foreach (static::parseTokens(array_diff($context_tokens, $optimized_tokens)) as $context_token) {
      [$context_id, $parameter] = $context_token;
      $context = $this->getService($context_id);
      $cacheable_metadata = $cacheable_metadata->merge($context->getCacheableMetadata($parameter));
    }

    sort($optimized_tokens);
    $keys = [];
    foreach (array_combine($optimized_tokens, static::parseTokens($optimized_tokens)) as $context_token => $context) {
      [$context_id, $parameter] = $context;
      $keys[] = '[' . $context_token . ']=' . $this->getService($context_id)->getContext($parameter);
    }

    // Create the returned object and merge in the cacheability metadata.     $context_cache_keys = new ContextCacheKeys($keys);
    return $context_cache_keys->merge($cacheable_metadata);
  }

  /** * Optimizes cache context tokens (the minimal representative subset). * * A minimal representative subset means that any cache context token in the * given set of cache context tokens that is a property of another cache * context cache context token in the set, is removed. * * Hence a minimal representative subset is the most compact representation * possible of a set of cache context tokens, that still captures the entire * universe of variations. * * If a cache context is being optimized away, it is able to set cacheable * metadata for itself which will be bubbled up. * * For example, when caching per user ('user'), also caching per role * ('user.roles') is meaningless because "per role" is implied by "per user". * * In the following examples, remember that the period indicates hierarchy and * the colon can be used to get a specific value of a calculated cache * context: * - ['a', 'a.b'] -> ['a'] * - ['a', 'a.b.c'] -> ['a'] * - ['a.b', 'a.b.c'] -> ['a.b'] * - ['a', 'a.b', 'a.b.c'] -> ['a'] * - ['x', 'x:foo'] -> ['x'] * - ['a', 'a.b.c:bar'] -> ['a'] * * @param string[] $context_tokens * A set of cache context tokens. * * @return string[] * A representative subset of the given set of cache context tokens.. */

  public static function years($min = 0, $max = 0, $required = FALSE) {
    // Ensure $min and $max are valid values.     if (empty($min)) {
      $min = intval(date('Y', REQUEST_TIME) - 3);
    }
    if (empty($max)) {
      $max = intval(date('Y', REQUEST_TIME) + 3);
    }
    $none = ['' => ''];
    $range = range($min, $max);
    $range = array_combine($range, $range);
    return !$required ? $none + $range : $range;
  }

  /** * Constructs an array of days in a month. * * @param bool $required * (optional) If FALSE, the returned array will include a blank value. * Defaults to FALSE. * @param int $month * (optional) The month in which to find the number of days. Defaults to * NULL. * @param int $year * (optional) The year in which to find the number of days. Defaults to * NULL. * * @return array * An array of days for the selected month. */

$elements = [
      '_info_file_ctime',
      'datestamp',
      'major',
      'name',
      'package',
      'project',
      'project status url',
      'version',
    ];
    $elements = array_merge($elements, $additional_elements);
    return array_intersect_key($info, array_combine($elements, $elements));
  }

}

/** * Constructs a TestLazyPluginCollection object. * * @param \Drupal\Component\Plugin\PluginManagerInterface $manager * The plugin manager that handles test plugins. */
  public function __construct(PluginManagerInterface $manager) {
    $this->manager = $manager;

    $instance_ids = array_keys($this->manager->getDefinitions());
    $this->instanceIds = array_combine($instance_ids, $instance_ids);
  }

  /** * {@inheritdoc} */
  protected function initializePlugin($instance_id) {
    $this->pluginInstances[$instance_id] = $this->manager->createInstance($instance_id, []);
  }

  /** * {@inheritdoc} */

// Test without menu name.     $this->assertSame($expected_link, $this->menuActiveTrail->getActiveLink());
  }

  /** * Tests getActiveTrailIds(). * * @covers ::getActiveTrailIds * @dataProvider provider */
  public function testGetActiveTrailIds(Request $request, $links, $menu_name, $expected_link, $expected_trail) {
    $expected_trail_ids = array_combine($expected_trail, $expected_trail);

    $this->requestStack->push($request);
    if ($links !== FALSE) {
      // We expect exactly two calls, one for the first call, and one after the       // cache clearing below.       $this->menuLinkManager->expects($this->exactly(2))
        ->method('loadLinksbyRoute')
        ->with('baby_llama')
        ->willReturn($links);
      if ($expected_link !== NULL) {
        $this->menuLinkManager->expects($this->exactly(2))

if (\count($customFieldAllowList) === 0) {
            $lineItem->setPayloadValue('customFields', []);

            return;
        }

        $lineItem->setPayloadValue(
            'customFields',
            array_intersect_key(
                $customFields,
                array_combine(
                    $customFieldAllowList,
                    $customFieldAllowList
                )
            )
        );
    }
}

  protected function replaceName($name, $data) {
    if (preg_match_all("/\[(.*)\]/U", $name, $matches)) {
      // Build our list of '[value]' => replacement.       $replace = [];
      foreach (array_combine($matches[0], $matches[1]) as $key => $value) {
        $replace[$key] = $this->replaceVariable($value, $data);
      }
      return strtr($name, $replace);
    }
    else {
      return $name;
    }
  }

  /** * Replaces variable values in included names with configuration data. * * Variable values are nested configuration keys that will be replaced by * their value or some of these special strings: * - '%key', will be replaced by the element's key. * - '%parent', to reference the parent element. * - '%type', to reference the schema definition type. Can only be used in * combination with %parent. * * There may be nested configuration keys separated by dots or more complex * patterns like '%parent.name' which references the 'name' value of the * parent element. * * Example patterns: * - 'name.subkey', indicates a nested value of the current element. * - '%parent.name', will be replaced by the 'name' value of the parent. * - '%parent.%key', will be replaced by the parent element's key. * - '%parent.%type', will be replaced by the schema type of the parent. * - '%parent.%parent.%type', will be replaced by the schema type of the * parent's parent. * * @param string $value * Variable value to be replaced. * @param mixed $data * Configuration data for the element. * * @return string * The replaced value if a replacement found or the original value if not. */

        if (\count($values) < \count($params)) {
            $params = \array_slice($params, 0, \count($values));
        } elseif (\count($values) > \count($params)) {
            $values[] = new EnumStub(array_splice($values, \count($params)), false);
            $params[] = $variadic;
        }
        if (['...'] === $params) {
            $this->dumpKeys = false;
            $this->value = $values[0]->value;
        } else {
            $this->value = array_combine($params, $values);
        }
    }

    private static function getParameters(string $function, ?string $class): array
    {
        if (isset(self::$parameters[$k = $class.'::'.$function])) {
            return self::$parameters[$k];
        }

        try {
            $r = null !== $class ? new \ReflectionMethod($class, $function) : new \ReflectionFunction($function);
        }

$ids->getIdArray(['tag-1', 'tag-2']),
        ];
    }

    /** * @param array<string> $ids * * @return array<string, mixed> */
    private static function keys(array $ids): array
    {
        $return = \array_combine($ids, \array_fill(0, \count($ids), true));

        static::assertIsArray($return);

        return $return;
    }
}

/** * Fetches a new blank row (not from the database). * * @param array $data OPTIONAL data to populate in the new row. * @param string $defaultSource OPTIONAL flag to force default values into new row * @return Zend_Db_Table_Row_Abstract */
    public function createRow(array $data = array(), $defaultSource = null)
    {
        $cols     = $this->_getCols();
        $defaults = array_combine($cols, array_fill(0, count($cols), null));

        // nothing provided at call-time, take the class value         if ($defaultSource == null) {
            $defaultSource = $this->_defaultSource;
        }

        if (!in_array($defaultSource, array(self::DEFAULT_CLASS, self::DEFAULT_DB, self::DEFAULT_NONE))) {
            $defaultSource = self::DEFAULT_NONE;
        }

        if ($defaultSource == self::DEFAULT_DB) {

$options['hide_alter_empty'] = ['default' => TRUE];

    return $options;
  }

  /** * Performs some cleanup tasks on the options array before saving it. */
  public function submitOptionsForm(&$form, FormStateInterface $form_state) {
    $options = &$form_state->getValue('options');
    $types = ['element_type', 'element_label_type', 'element_wrapper_type'];
    $classes = array_combine(['element_class', 'element_label_class', 'element_wrapper_class'], $types);

    foreach ($types as $type) {
      if (!$options[$type . '_enable']) {
        $options[$type] = '';
      }
    }

    foreach ($classes as $class => $type) {
      if (!$options[$class . '_enable'] || !$options[$type . '_enable']) {
        $options[$class] = '';
      }
    }