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. Its equivalent for iterators is Nette\Utils\Iterables.

Following examples assume the following class alias is defined:

use Nette\Utils\Arrays;

associate(array $array, mixed $path): array|\stdClass

The function flexibly transforms the $array into an associative array or objects according to the specified path $path. The path can be a string or an array. It consists of the names of keys in the input array and operators like ‘[]’, ‘->’, ‘=’, and ‘|’. Throws Nette\InvalidArgumentException if the path is invalid.

// converting to an associative array using a simple key
$arr = [
    ['name' => 'John', 'age' => 11],
    ['name' => 'Mary', 'age' => null],
    // ...
];
$result = Arrays::associate($arr, 'name');
// $result = ['John' => ['name' => 'John', 'age' => 11], 'Mary' => ['name' => 'Mary', 'age' => null]]
// assigning values from one key to another using the = operator
$result = Arrays::associate($arr, 'name=age'); // or ['name', '=', 'age']
// $result = ['John' => 11, 'Mary' => null, ...]
// creating an object using the -> operator
$result = Arrays::associate($arr, '->name'); // or ['->', 'name']
// $result = (object) ['John' => ['name' => 'John', 'age' => 11], 'Mary' => ['name' => 'Mary', 'age' => null]]
// combining keys using the | operator
$result = Arrays::associate($arr, 'name|age'); // or ['name', '|', 'age']
// $result: ['John' => ['name' => 'John', 'age' => 11], 'Paul' => ['name' => 'Paul', 'age' => 44]]
// adding to an array using []
$result = Arrays::associate($arr, 'name[]'); // or ['name', '[]']
// $result: ['John' => [['name' => 'John', 'age' => 22], ['name' => 'John', 'age' => 11]]]

contains(array $array, $value)bool

Tests an array for the presence of value. Uses a strict comparison (===)

Arrays::contains([1, 2, 3], 1);    // true
Arrays::contains(['1', false], 1); // false

every(array $array, callable $predicate)bool

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

$array = [1, 30, 39, 29, 10, 13];
$isBelowThreshold = fn($value) => $value < 40;
$res = Arrays::every($array, $isBelowThreshold); // true

See some().

filter(array $array, callable $predicate)array

Returns a new array containing all key-value pairs matching the given $predicate. The callback has the signature function ($value, int|string $key, array $array): bool.

Arrays::filter(
	['a' => 1, 'b' => 2, 'c' => 3],
	fn($v) => $v < 3,
);
// ['a' => 1, 'b' => 2]

first(array $array, ?callable $predicate=null, ?callable $else=null)mixed

Returns the first item (matching the specified predicate if given). If there is no such item, it returns result of invoking $else or null. The $predicate has the signature function ($value, int|string $key, array $array): bool.

It does not change the internal pointer unlike reset(). The $predicate and $else parameters exist since version 4.0.4.

Arrays::first([1, 2, 3]);                   // 1
Arrays::first([1, 2, 3], fn($v) => $v > 2); // 3
Arrays::first([]);                          // null
Arrays::first([], else: fn() => false);     // false

See last().

firstKey(array $array, ?callable $predicate=null): int|string|null

Returns the key of first item (matching the specified predicate if given) or null if there is no such item. The $predicate has the signature function ($value, int|string $key, array $array): bool.

Arrays::firstKey([1, 2, 3]);                   // 0
Arrays::firstKey([1, 2, 3], fn($v) => $v > 2); // 2
Arrays::firstKey(['a' => 1, 'b' => 2]);        // 'a'
Arrays::firstKey([]);                          // null

See lastKey().

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

Transforms 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, bool $invert=false)array

Returns only those array items, which matches a regular expression $pattern. If $invert is true, it returns elements that do not match. Regex compilation or runtime error throws Nette\RegexpException.

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

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

Inserts the contents of the $inserted array into the $array immediately after the $key. If $key is null (or 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|null $key, array $inserted)void

Inserts the contents of the $inserted array into the $array before the $key. If $key is null (or 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];

invoke(iterable $callbacks, …$args)array

Invokes all callbacks and returns array of results.

$callbacks = [
	'+' => fn($a, $b) => $a + $b,
	'*' => fn($a, $b) => $a * $b,
];

$array = Arrays::invoke($callbacks, 5, 11);
// $array = ['+' => 16, '*' => 55];

invokeMethod(iterable $objects, string $method, …$args)array

Invokes method on every object in an array and returns array of results.

$objects = ['a' => $obj1, 'b' => $obj2];

$array = Arrays::invokeMethod($objects, 'foo', 1, 2);
// $array = ['a' => $obj1->foo(1, 2), 'b' => $obj2->foo(1, 2)];

isList(array $array): bool

Checks 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

last(array $array, ?callable $predicate=null, ?callable $else=null)mixed

Returns the last item (matching the specified predicate if given). If there is no such item, it returns result of invoking $else or null. The $predicate has the signature function ($value, int|string $key, array $array): bool.

It does not change the internal pointer unlike end(). The $predicate and $else parameters exist since version 4.0.4.

Arrays::last([1, 2, 3]);                   // 3
Arrays::last([1, 2, 3], fn($v) => $v < 3); // 2
Arrays::last([]);                          // null
Arrays::last([], else: fn() => false);     // false

See first().

lastKey(array $array, ?callable $predicate=null): int|string|null

Returns the key of last item (matching the specified predicate if given) or null if there is no such item. The $predicate has the signature function ($value, int|string $key, array $array): bool.

Arrays::lastKey([1, 2, 3]);                    // 2
Arrays::lastKey([1, 2, 3], fn($v) => $v < 3);  // 1
Arrays::lastKey(['a' => 1, 'b' => 2]);         // 'b'
Arrays::lastKey([]);                           // null

See firstKey().

map(array $array, callable $transformer)array

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

$array = ['foo', 'bar', 'baz'];
$res = Arrays::map($array, fn($value) => $value . $value);
// $res = ['foofoo', 'barbar', 'bazbaz']

mergeTree(array $array1, array $array2)array

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 $array, 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 &$array, 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)bool

Renames a key. Returns true if the key was found in the array.

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

getKeyOffset(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];
$position = Arrays::getKeyOffset($array, 'first'); // returns 0
$position = Arrays::getKeyOffset($array, 'second'); // returns 1
$position = Arrays::getKeyOffset($array, 'not-exists'); // returns null

some(array $array, callable $predicate)bool

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

$array = [1, 2, 3, 4];
$isEven = fn($value) => $value % 2 === 0;
$res = Arrays::some($array, $isEven); // true

See every().

toKey(mixed $key): string|int

Converts a value to an array key, which is either an integer or a string.

Arrays::toKey('1');  // 1
Arrays::toKey('01'); // '01'

toObject(iterable $array, object $object)object

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

$obj = new stdClass;
$array = ['foo' => 1, 'bar' => 2];
Arrays::toObject($array, $obj); // it sets $obj->foo = 1; $obj->bar = 2;

wrap(array $array, string $prefix='', string $suffix='')array

It casts each element of array to string and encloses it with $prefix and $suffix.

$array = Arrays::wrap(['a' => 'red', 'b' => 'green'], '<<', '>>');
// $array = ['a' => '<<red>>', 'b' => '<<green>>'];

ArrayHash

Object Nette\Utils\ArrayHash is the descendant of generic class 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
$hash->foo; // 123

You can use the count($hash) function to get the number of elements.

You can iterate over an object as you would an array, even with a reference:

foreach ($hash as $key => $value) {
	// ...
}

foreach ($hash as $key => &$value) {
	$value = 'new value';
}

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

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

$hash = Nette\Utils\ArrayHash::from($array);
$hash->foo; // 123
$hash->bar; // 456

The transformation is recursive:

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

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

It can be avoided by the second parameter:

$hash = Nette\Utils\ArrayHash::from($array, false);
$hash->inner; // array

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

You can use the count($list) function to get the number of items.

You can iterate over an object as you would an array, even with a reference:

foreach ($list as $key => $value) {
	// ...
}

foreach ($list as $key => &$value) {
	$value = 'new value';
}

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

$array = ['foo', 'bar'];
$list = Nette\Utils\ArrayList::from($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:

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

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

$list->prepend('d');
// ArrayList(0 => 'd', 1 => 'a', 2 => 'c')
version: 4.0 3.x 2.x