iterator_to_array

(PHP 5 >= 5.1.0, PHP 7, PHP 8)

iterator_to_array — Copiar el iterador a un array

Descripción

iterator_to_array(Traversable $iterator, bool $use_keys = true): array

Copia los elementos de un iterador a un array.

Parámetros

iterator

El iterador a copiar.

use_keys

Si usar las claves del elemento iterador como índice.

En PHP 5.5 y posterior, si una clave es un array u object, se generará una advertencia. Las claves null serán convertidas a un string vacío, las claves float serán truncadas a su equivalente integer, las claves resource generarán una advertencia y serán convertidas a sus ID de recurso, y las claves boolean serán convertidas a enteros.

Nota:
Si no se establece este parámetro o se establece a true, las claves duplicadas serán sobrescritas. El último valor con una clave dada estará en el array devuelto. Para obtener todos los valores en cualquier caso, se ha de establecer este parámetro a false.

Valores devueltos

Un array que contiene los elementos del iterator.

Historial de cambios

Versión	Descripción
5.5.0	iterator_to_array() da soporte a tipos de claves diferentes a integer y string cuando el parámetro `use_keys` está habilitado.
5.2.1	Añadido el parámetro `use_keys`.

Ejemplos

Ejemplo #1 Ejemplo de iterator_to_array()

<?php
$iterator = new ArrayIterator(array('recipe'=>'panqueques', 'huevo', 'leche', 'harina'));
var_dump(iterator_to_array($iterator, true));
var_dump(iterator_to_array($iterator, false));
?>

El resultado del ejemplo sería:

array(4) {
  ["recipe"]=>
  string(10) "panqueques"
  [0]=>
  string(5) "huevo"
  [1]=>
  string(5) "leche"
  [2]=>
  string(6) "harina"
}
array(4) {
  [0]=>
  string(10) "panqueques"
  [1]=>
  string(5) "huevo"
  [2]=>
  string(5) "leche"
  [3]=>
  string(6) "harina"
}

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User Contributed Notes 4 notes

down

wizzard351 at yahoo dot com ¶

2 years ago

One important thing to remember is that in iterator can be infinite. Not all iterators necessarily end. If iterator_to_array is used on such an iterator, it will exhaust the available memory, and throw a fatal error.

For example, consider the following code:

<?php

function fibonacci(): Generator
{
    yield $a = 1;
    yield $b = 2;

    start:
    yield $c = $a + $b;
    $a = $b;
    $b = $c;
    goto start;
}

$fibonacciSequence = fibonacci();
iterator_to_array($fibonacciSequence);

?>

Since <?php fibonacci(); ?> generates an infinite fibonacci sequence, which is valid, since it is actually an infinite sequence, then attempting to convert it to an array will fail.

down

jerome at yazo dot net ¶

16 years ago

Using the boolean param :



<?php



$first = new ArrayIterator( array('k1' => 'a' , 'k2' => 'b',  'k3' => 'c',  'k4' => 'd') );

$second = new ArrayIterator( array( 'k1' => 'X', 'k2' => 'Y', 'Z' ) );



$combinedIterator= new AppendIterator();

$combinedIterator->append( $first );

$combinedIterator->append( $second );



var_dump( iterator_to_array($combinedIterator, false) );



?>



will output : 



array(7) (

  [0]=>

  string(1) "a"

  [1]=>

  string(1) "b"

  [2]=>

  string(1) "c"

  [3]=>

  string(1) "d"

  [4]=>

  string(1) "X"

  [5]=>

  string(1) "Y"

  [6]=>

  string(1) "Z"

)



<?php



var_dump( iterator_to_array($combinedIterator, true) );



?>



will output (since keys would merge) :



array(5) (

  ["k1"]=>

  string(1) "X"

  ["k2"]=>

  string(1) "Y"

  ["k3"]=>

  string(1) "c"

  ["k4"]=>

  string(1) "d"

  [0]=>

  string(1) "Z"

)

down

joksnet at gmail dot com ¶

10 years ago

To generate an deep array from nested iterators:

<?php
function iterator_to_array_deep(\Traversable $iterator, $use_keys = true) {
    $array = array();
    foreach ($iterator as $key => $value) {
        if ($value instanceof \Iterator) {
            $value = iterator_to_array_deep($value, $use_keys);
        }
        if ($use_keys) {
            $array[$key] = $value;
        } else {
            $array[] = $value;
        }
    }
    return $array;
}
?>

I use it to test an iterator: https://gist.github.com/jm42/cb328106f393eeb28751

down

Harry Willis ¶

9 years ago

When using iterator_to_array() on an SplObjectStorage object, it's advisable to set $use_keys to false.

The resulting array is identical, since the iterator keys produced by SplObjectStorage::key() are always integers from 0 to (COUNT-1). Passing $use_keys=false cuts out the unnecessary calls to SplObjectStorage::key(), giving a slight performance advantage.

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