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;
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 (iterable $array, 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 $array): bool.
$array = [1, 30, 39, 29, 10, 13];
$isBelowThreshold = function ($value): bool { return $value < 40; };
$res = Arrays::every($array, $isBelowThreshold); // true
See some().
first (array $array): mixed
Returns the first item from the array or null if array is empty. It does not change the internal pointer unlike
reset().
Arrays::first([1, 2, 3]); // 1
Arrays::first([]); // null
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, 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|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.
$callbacks = [
'+' => function ($a, $b) { return $a + $b; },
'*' => function ($a, $b) { return $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): mixed
Returns the last item from the array or null if array is empty. It does not change the internal pointer unlike
end().
Arrays::last([1, 2, 3]); // 3
Arrays::last([]); // null
map (iterable $array, 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 $array): 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
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 (since v3.1.3).
$array = ['first' => 10, 'second' => 20];
Arrays::renameKey($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];
$position = Arrays::searchKey($array, 'first'); // returns 0
$position = Arrays::searchKey($array, 'second'); // returns 1
$position = Arrays::searchKey($array, 'not-exists'); // returns null
Prior to nette/utils 3.2, the method was named searchKey(). In version 2, it returned
false instead of null.
some (iterable $array, 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 $array): bool.
$array = [1, 2, 3, 4];
$isEven = function ($value): bool { return $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 (iterable $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
$hash->foo; // 123
You can use count() and iterate over the object, as in the case of the array:
count($hash); // 2
foreach ($hash as $key => $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
Over the object you can iterate or call count(), as in the case of an array.
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')
