filter() public static method (available since version 2.0.9)

Filters array according to rules specified.

For example:

$array = [
    'A' => [1, 2],
    'B' => [
        'C' => 1,
        'D' => 2,
    ],
    'E' => 1,
];

$result = \yii\helpers\ArrayHelper::filter($array, ['A']);
// $result will be:
// [
//     'A' => [1, 2],
// ]

$result = \yii\helpers\ArrayHelper::filter($array, ['A', 'B.C']);
// $result will be:
// [
//     'A' => [1, 2],
//     'B' => ['C' => 1],
// ]

$result = \yii\helpers\ArrayHelper::filter($array, ['B', '!B.C']);
// $result will be:
// [
//     'B' => ['D' => 2],
// ]

getColumn() public static method

Returns the values of a specified column in an array.

The input array should be multidimensional or an array of objects.

For example,

$array = [
    ['id' => '123', 'data' => 'abc'],
    ['id' => '345', 'data' => 'def'],
];
$result = ArrayHelper::getColumn($array, 'id');
// the result is: ['123', '345']

// using anonymous function
$result = ArrayHelper::getColumn($array, function ($element) {
    return $element['id'];
});

getValue() public static method

Retrieves the value of an array element or object property with the given key or property name.

If the key does not exist in the array or object, the default value will be returned instead.

The key may be specified in a dot format to retrieve the value of a sub-array or the property of an embedded object. In particular, if the key is x.y.z, then the returned value would be $array['x']['y']['z'] or $array->x->y->z (if $array is an object). If $array['x'] or $array->x is neither an array nor an object, the default value will be returned. Note that if the array already has an element x.y.z, then its value will be returned instead of going through the sub-arrays. So it is better to be done specifying an array of key names like ['x', 'y', 'z'].

Below are some usage examples,

// working with array
$username = \yii\helpers\ArrayHelper::getValue($_POST, 'username');
// working with object
$username = \yii\helpers\ArrayHelper::getValue($user, 'username');
// working with anonymous function
$fullName = \yii\helpers\ArrayHelper::getValue($user, function ($user, $defaultValue) {
    return $user->firstName . ' ' . $user->lastName;
});
// using dot format to retrieve the property of embedded object
$street = \yii\helpers\ArrayHelper::getValue($users, 'address.street');
// using an array of keys to retrieve the value
$value = \yii\helpers\ArrayHelper::getValue($versions, ['1.0', 'date']);

htmlDecode() public static method

Decodes HTML entities into the corresponding characters in an array of strings.

Only array values will be decoded by default. If a value is an array, this method will also decode it recursively. Only string values will be decoded.

See also http://www.php.net/manual/en/function.htmlspecialchars-decode.php.

htmlEncode() public static method

Encodes special characters in an array of strings into HTML entities.

Only array values will be encoded by default. If a value is an array, this method will also encode it recursively. Only string values will be encoded.

See also http://www.php.net/manual/en/function.htmlspecialchars.php.

index() public static method

Indexes and/or groups the array according to a specified key.

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:

$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

[
    '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.

$result = ArrayHelper::index($array, function ($element) {
    return $element['id'];
});

Passing id as a third argument will group $array by id:

$result = ArrayHelper::index($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:

[
    '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:

$result = ArrayHelper::index($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:

[
    '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']
        ]
    ]
]

isAssociative() public static method

Returns a value indicating whether the given array is an associative array.

An array is associative if all its keys are strings. If $allStrings is false, then an array will be treated as associative if at least one of its keys is a string.

Note that an empty array will NOT be considered associative.

isIn() public static method (available since version 2.0.7)

Check whether an array or Traversable contains an element.

This method does the same as the PHP function in_array() but additionally works for objects that implement the Traversable interface.

See also http://php.net/manual/en/function.in-array.php.

isIndexed() public static method

Returns a value indicating whether the given array is an indexed array.

An array is indexed if all its keys are integers. If $consecutive is true, then the array keys must be a consecutive sequence starting from 0.

Note that an empty array will be considered indexed.

isSubset() public static method (available since version 2.0.7)

Checks whether an array or Traversable is a subset of another array or Traversable.

This method will return true, if all elements of $needles are contained in $haystack. If at least one element is missing, false will be returned.

isTraversable() public static method (available since version 2.0.8)

Checks whether a variable is an array or Traversable.

This method does the same as the PHP function is_array() but additionally works on objects that implement the Traversable interface.

See also http://php.net/manual/en/function.is-array.php.

keyExists() public static method

Checks if the given array contains the specified key.

This method enhances the array_key_exists() function by supporting case-insensitive key comparison.

map() public static method

Builds a map (key-value pairs) from a multidimensional array or an array of objects.

The $from and $to parameters specify the key names or property names to set up the map. Optionally, one can further group the map according to a grouping field $group.

For example,

$array = [
    ['id' => '123', 'name' => 'aaa', 'class' => 'x'],
    ['id' => '124', 'name' => 'bbb', 'class' => 'x'],
    ['id' => '345', 'name' => 'ccc', 'class' => 'y'],
];

$result = ArrayHelper::map($array, 'id', 'name');
// the result is:
// [
//     '123' => 'aaa',
//     '124' => 'bbb',
//     '345' => 'ccc',
// ]

$result = ArrayHelper::map($array, 'id', 'name', 'class');
// the result is:
// [
//     'x' => [
//         '123' => 'aaa',
//         '124' => 'bbb',
//     ],
//     'y' => [
//         '345' => 'ccc',
//     ],
// ]

merge() public static method

Merges two or more arrays into one recursively.

If each array has an element with the same string key value, the latter will overwrite the former (different from array_merge_recursive). Recursive merging will be conducted if both arrays have an element of array type and are having the same key. For integer-keyed elements, the elements from the latter array will be appended to the former array. You can use yii\helpers\UnsetArrayValue object to unset value from previous array or yii\helpers\ReplaceArrayValue to force replace former value instead of recursive merging.

multisort() public static method

Sorts an array of objects or arrays (with the same structure) by one or several keys.

remove() public static method

Removes an item from an array and returns the value. If the key does not exist in the array, the default value will be returned instead.

Usage examples,

// $array = ['type' => 'A', 'options' => [1, 2]];
// working with array
$type = \yii\helpers\ArrayHelper::remove($array, 'type');
// $array content
// $array = ['options' => [1, 2]];

removeValue() public static method (available since version 2.0.11)

Removes items with matching values from the array and returns the removed items.

Example,

$array = ['Bob' => 'Dylan', 'Michael' => 'Jackson', 'Mick' => 'Jagger', 'Janet' => 'Jackson'];
$removed = \yii\helpers\ArrayHelper::removeValue($array, 'Jackson');
// result:
// $array = ['Bob' => 'Dylan', 'Mick' => 'Jagger'];
// $removed = ['Michael' => 'Jackson', 'Janet' => 'Jackson'];

toArray() public static method

Converts an object or an array of objects into an array.

[
    'app\models\Post' => [
        'id',
        'title',
        // the key name in array result => property name
        'createTime' => 'created_at',
        // the key name in array result => anonymous function
        'length' => function ($post) {
            return strlen($post->content);
        },
    ],
]

[
    'id' => 123,
    'title' => 'test',
    'createTime' => '2013-01-01 12:00AM',
    'length' => 301,
]