Array Functions

This page is about the Nette\Utils\Arrays, ArrayHash and ArrayList classes, which are related to arrays.

Installation:

composer require nette/utils

Arrays

Nette\Utils\Arrays is a static class, which contains a handful of handy array functions.

Following examples assume the following class alias is defined:

use Nette\Utils\Arrays;

every(array $arr, callable $callback): bool

Tests whether all elements in the array pass the test implemented by the provided function, which has the signature function ($value, $key, array $arr): bool.

$array = [1, 30, 39, 29, 10, 13];
$isBelowThreshold = function ($value): bool { return $value < 40; };
$res = Arrays::every($array, $isBelowThreshold); // false

flatten(array $array, bool $preserveKeys=false): array

Transform multidimensional array to flat array.

$array = Arrays::flatten([1, 2, [3, 4, [5, 6]]]);
// $array = [1, 2, 3, 4, 5, 6];

get(array $array, string|int|array $key, mixed $default=null): mixed

Returns $array[$key] item. If it does not exist, Nette\InvalidArgumentException is thrown, unless a default value is set as third argument.

// if $array['foo'] does not exist, throws an exception
$value = Arrays::get($array, 'foo');

// if $array['foo'] does not exist, returns 'bar'
$value = Arrays::get($array, 'foo', 'bar');

Argument $key may as well be an array.

$array = ['color' => ['favorite' => 'red'], 5];

$value = Arrays::get($array, ['color', 'favorite']);
// returns 'red'

getRef(array &$array, string|int|array $key): mixed

Gets reference to given $array[$key]. If the index does not exist, new one is created with value null.

$valueRef = & Arrays::getRef($array, 'foo');
// returns $array['foo'] reference

Works with multidimensional arrays as well as get().

$value = & Arrays::get($array, ['color', 'favorite']);
// returns $array['color']['favorite'] reference

grep(array $array, string $pattern, int $flags=null): array

Returns only those array items, which matches a regular expression $pattern. Regex compilation or runtime error throws Nette\RegexpException.

$filteredArray = Arrays::grep($array, '~^\d+$~');
// returns only numerical items

Value PREG_GREP_INVERT may be set as $flags, which inverts the selection.

insertAfter(array &$array, string|int $key, array $inserted): void

Inserts the contents of the $inserted array into the $array immediately after the $key. If the key does not exist, it is inserted at the end.

$array = ['first' => 10, 'second' => 20];
Arrays::insertAfter($array, 'first', ['hello' => 'world']);
// $array = ['first' => 10, 'hello' => 'world', 'second' => 20];

insertBefore(array &$array, string|int $key, array $inserted): void

Inserts the contents of the $inserted array into the $array before the $key. If the key does not exist, it is inserted at the beginning.

$array = ['first' => 10, 'second' => 20];
Arrays::insertBefore($array, 'first', ['hello' => 'world']);
// $array = ['hello' => 'world', 'first' => 10, 'second' => 20];

isList(array $array): bool

Check if the array is indexed in ascending order of numeric keys from zero, a.k.a list.

Arrays::isList(['a', 'b', 'c'])); // true
Arrays::isList([4 => 1, 2, 3])); // false
Arrays::isList(['a' => 1, 'b' => 2])); // false

map(array $arr, callable $callback): array

Calls $callback on all elements in the array and returns the array of return values. The callback has the signature function ($value, $key, array $arr): bool.

$array = ['foo', 'bar', 'baz'];
$res = Arrays::map($array, function ($value): string { return $value . $value; });
// $res = ['foofoo', 'barbar', 'bazbaz']

mergeTree(array $array1, array $array2): array

It recursively merges two fields. It is useful, for example, for merging tree structures. It behaves as the + operator for array, ie. it adds a key/value pair from the second array to the first one and retains the value from the first array in the case of a key collision.

$array1 = ['color' => ['favorite' => 'red'], 5];
$array2 = [10, 'color' => ['favorite' => 'green', 'blue']];

$array = Arrays::mergeTree($array1, $array2);
// $array = ['color' => ['favorite' => 'red', 'blue'], 5];

Values from the second array are always appended to the first. The disappearance of the value 10 from the second array may seem a bit confusing. It should be noted that this value as well as the value 5 in the first array have the same numeric key 0, so in the resulting field there is only an element from the first array.

normalize(array $arr, string $filling=null): array

Normalizes array to associative array. Replace numeric keys with their values, the new value will be $filling.

$array = Arrays::normalize([1 => 'first', 'a' => 'second']);
// $array = ['first' => null, 'a' => 'second'];

$array = Arrays::normalize([1 => 'first', 'a' => 'second'], 'foobar');
// $array = ['first' => 'foobar', 'a' => 'second'];

pick(array &$arr, string|int $key, mixed $default=null): mixed

Returns and removes the value of an item from an array. If it does not exist, it throws an exception, or returns $default, if provided.

$array = [1 => 'foo', null => 'bar'];
$a = Arrays::pick($array, null);
// $a = 'bar'
$b = Arrays::pick($array, 'not-exists', 'foobar');
// $b = 'foobar'
$c = Arrays::pick($array, 'not-exists');
// throws Nette\InvalidArgumentException

renameKey(array &$array, string|int $oldKey, string|int $newKey): void

Renames a key.

$array = ['first' => 10, 'second' => 20];
Arrays::renameKey($array, 'first', 'renamed');
// $array = ['renamed' => 10, 'second' => 20];

searchKey(array $array, string|int $key): ?int

Returns zero-indexed position of given array key. Returns null if key is not found.

$array = ['first' => 10, 'second' => 20];
$position = Arrays::searchKey($array, 'first'); // returns 0
$position = Arrays::searchKey($array, 'second'); // returns 1
$position = Arrays::searchKey($array, 'not-exists'); // returns null

Version 2 returns false instead of null.

some(array $arr, callable $callback): bool

Tests whether at least one element in the array passes the test implemented by the provided callback with signature function ($value, $key, array $arr): bool.

$array = [1, 2, 3, 4];
$isEven = function ($value): bool { return $value % 2 === 0; };
$res = Arrays::some($array, $isEven); // true

toObject(array $arr, object $obj): object

Copies the elements of the $arr array to the $obj object and returns it.

$obj = new stdClass;
Arrays::toObject(['foo' => 'bar'], $obj);
echo $obj->foo; // 'bar'

ArrayHash

Object Nette\Utils\ArrayHash is the descendant of an anonymous stdClass and extends it to the ability to treat it as an array, for example, accessing members using square brackets:

$hash = new Nette\Utils\ArrayHash;
$hash['foo'] = 123;
$hash->bar = 456; // also works object notation
echo $hash->foo; // 123

You can use count() and iterate over the object, as in the case of the array:

echo count($hash); // 2

foreach ($hash as $key => $value) ...

Existing arrays can be transformed to ArrayHash using from():

$array = ['foo' => 123, 'bar' => 456, 'inner' => ['a' => 'b']];

$hash = Nette\Utils\ArrayHash::from($array);
echo $hash->foo; // 123
echo $hash->inner; // ArrayHash('a' => 'b')
echo $hash->inner->a; // 'b'
echo $hash['inner']['a']; // 'b'

The transformation is recursive, which can be avoided by the second parameter:

$hash = Nette\Utils\ArrayHash::from($array, false);
echo $hash->inner; // array ['a' => 'b']

Transform back to the array:

$array = (array) $hash;

ArrayList

Nette\Utils\ArrayList represents a linear array where the indexes are only integers ascending from 0.

$list = new Nette\Utils\ArrayList;
$list[] = 'a';
$list[] = 'b';
$list[] = 'c';
// ArrayList(0 => 'a', 1 => 'b', 2 => 'c')
echo count($list); // 3

Over the object you can iterate or call count(), as in the case of an array.

Accessing keys beyond the allowed values throws an exception Nette\OutOfRangeException:

echo $list[-1]; // throws Nette\OutOfRangeException
unset($list[30]); // throws Nette\OutOfRangeException

Removing the key will result in renumbering the elements:

// ArrayList(0 => 'a', 1 => 'c')
unset($list[1]);

You can add a new element to the beginning using prepend():

$list->prepend('d');
// ArrayList(0 => 'd', 1 => 'a', 2 => 'c')