Iterator Functions
Nette\Utils\Iterables is a static class with functions for working with iterators. Its counterpart for arrays is Nette\Utils\Arrays.
Installation:
composer require nette/utils
All examples assume the creation of an alias:
use Nette\Utils\Iterables;
contains(iterable $iterable, $value): bool
Tests for the presence of a value in the iterator. It uses strict comparison (===
).
Iterables::contains(new ArrayIterator([1, 2, 3]), 1); // true
Iterables::contains(new ArrayIterator([1, 2, 3]), '1'); // false
containsKey(iterable $iterable, $value): bool
Tests for the presence of a key in the iterator. It uses strict comparison (===
).
Iterables::containsKey(new ArrayIterator([1, 2, 3]), 0); // true
Iterables::containsKey(new ArrayIterator([1, 2, 3]), 4); // false
every(iterable $iterable, callable $predicate): bool
Tests whether all elements of the iterator pass a test implemented in $predicate
with the signature
function ($value, $key, iterable $iterable): bool
.
$iterator = new ArrayIterator([1, 30, 39, 29, 10, 13]);
$isBelowThreshold = fn($value) => $value < 40;
$res = Iterables::every($iterator, $isBelowThreshold); // true
See some().
filter(iterable $iterable, callable $predicate): Generator
Iterator that filters elements according to a predicate. The predicate has the signature
function ($value, $key, iterable $iterable): bool
. Maintains original keys.
$iterator = new ArrayIterator([1, 2, 3]);
$iterator = Iterables::filter($iterator, fn($v) => $v < 3);
// 1, 2
first(iterable $iterable, ?callable $predicate=null, ?callable $else=null): mixed
Returns the first item (matching the predicate, if specified). If no such item exists, returns the result of calling
$else
or null. The $predicate
parameter has the signature
function ($value, $key, iterable $iterable): bool
.
Iterables::first(new ArrayIterator([1, 2, 3])); // 1
Iterables::first(new ArrayIterator([1, 2, 3]), fn($v) => $v > 2); // 3
Iterables::first(new ArrayIterator([])); // null
Iterables::first(new ArrayIterator([]), else: fn() => false); // false
firstKey(iterable $iterable, ?callable $predicate=null, ?callable $else=null): mixed
Returns the key of the first item (matching the predicate, if specified). If no such item exists, returns the result of calling
$else
or null. The predicate has the signature function ($value, $key, iterable $iterable): bool
.
Iterables::firstKey(new ArrayIterator([1, 2, 3])); // 0
Iterables::firstKey(new ArrayIterator([1, 2, 3]), fn($v) => $v > 2); // 2
Iterables::firstKey(new ArrayIterator(['a' => 1, 'b' => 2])); // 'a'
Iterables::firstKey(new ArrayIterator([])); // null
map(iterable $iterable, callable $transformer): array
Iterator that transforms values by calling $transformer
. It has the signature
function ($value, $key, iterable $iterable): bool
. Maintains original keys.
$iterator = new ArrayIterator([1, 2, 3]);
$iterator = Iterables::map($iterator, fn($v) => $v * 2);
// 2, 4, 6
some(iterable $iterable, callable $predicate): bool
Tests whether at least one element of the iterator passes a test implemented in $predicate
with the signature
function ($value, $key, iterable $iterable): bool
.
$iterator = new ArrayIterator([1, 30, 39, 29, 10, 13]);
$isEven = fn($value) => $value % 2 === 0;
$res = Iterables::some($iterator, $isEven); // true
See every().