yii\helpers\BaseArrayHelper::index PHP Method

BaseArrayHelper Class Documentation Datei anzeigen Open project: yiisoft/yii2

index() public static method

The input should be either multidimensional array or an array of objects. The $key can be either a key name of the sub-array, a property name of object, or an anonymous function that must return the value that will be used as a key. $groups is an array of keys, that will be used to group the input array into one or more sub-arrays based on keys specified. If the $key is specified as null or a value of an element corresponding to the key is null in addition to $groups not specified then the element is discarded. For example: php $array = [ ['id' => '123', 'data' => 'abc', 'device' => 'laptop'], ['id' => '345', 'data' => 'def', 'device' => 'tablet'], ['id' => '345', 'data' => 'hgi', 'device' => 'smartphone'], ]; $result = ArrayHelper::index($array, 'id'); The result will be an associative array, where the key is the value of id attribute php [ '123' => ['id' => '123', 'data' => 'abc', 'device' => 'laptop'], '345' => ['id' => '345', 'data' => 'hgi', 'device' => 'smartphone'] The second element of an original array is overwritten by the last element because of the same id ] An anonymous function can be used in the grouping array as well. php $result = ArrayHelper::index($array, function ($element) { return $element['id']; }); Passing id as a third argument will group $array by id: php $result = ArrayHelper::index($array, null, 'id'); The result will be a multidimensional array grouped by id on the first level, by device on the second level and indexed by data on the third level: php [ '123' => [ ['id' => '123', 'data' => 'abc', 'device' => 'laptop'] ], '345' => [ // all elements with this index are present in the result array ['id' => '345', 'data' => 'def', 'device' => 'tablet'], ['id' => '345', 'data' => 'hgi', 'device' => 'smartphone'], ] ] The anonymous function can be used in the array of grouping keys as well: php $result = ArrayHelper::index($array, 'data', [function ($element) { return $element['id']; }, 'device']); The result will be a multidimensional array grouped by id on the first level, by the device on the second one and indexed by the data on the third level: php [ '123' => [ 'laptop' => [ 'abc' => ['id' => '123', 'data' => 'abc', 'device' => 'laptop'] ] ], '345' => [ 'tablet' => [ 'def' => ['id' => '345', 'data' => 'def', 'device' => 'tablet'] ], 'smartphone' => [ 'hgi' => ['id' => '345', 'data' => 'hgi', 'device' => 'smartphone'] ] ] ]

public static index ( array $array, string \| Closure \| null $key, string \| string[] \| Closure[] \| null $groups = [] ) : array
$array	array	the array that needs to be indexed or grouped
$key	string \| Closure \| null	the column name or anonymous function which result will be used to index the array
$groups	string \| string[] \| Closure[] \| null	the array of keys, that will be used to group the input array by one or more keys. If the $key attribute or its value for the particular element is null and $groups is not defined, the array element will be discarded. Otherwise, if $groups is specified, array element will be added to the result array without any key. This parameter is available since version 2.0.8.
return	array	the indexed and/or grouped array

    public static function index($array, $key, $groups = [])
    {
        $result = [];
        $groups = (array) $groups;
        foreach ($array as $element) {
            $lastArray =& $result;
            foreach ($groups as $group) {
                $value = static::getValue($element, $group);
                if (!array_key_exists($value, $lastArray)) {
                    $lastArray[$value] = [];
                }
                $lastArray =& $lastArray[$value];
            }
            if ($key === null) {
                if (!empty($groups)) {
                    $lastArray[] = $element;
                }
            } else {
                $value = static::getValue($element, $key);
                if ($value !== null) {
                    if (is_float($value)) {
                        $value = (string) $value;
                    }
                    $lastArray[$value] = $element;
                }
            }
            unset($lastArray);
        }
        return $result;
    }

BaseArrayHelper

filter

getColumn

getValue

htmlDecode

htmlEncode

index

isAssociative

isIn

isIndexed

isSubset

isTraversable

keyExists

map

merge

multisort

remove

removeValue

toArray