La clase ArrayIterator

(PHP 5, PHP 7, PHP 8)

Introducción

Este iterador permite eliminar y modificar valores y claves cuando se recorren arrays y objetos.

Cuando se quiere iterar sobre el mismo array varias veces, se necesita instanciar ArrayObject y dejarle que cree instancias ArrayIterator que hacen referencia a la misma usando foreach o llamando a su método getIterator() de forma manual.

Sinopsis de la Clase

class ArrayIterator implements SeekableIterator, ArrayAccess, Serializable, Countable {
/* Constantes */
public const int STD_PROP_LIST;
public const int ARRAY_AS_PROPS;
/* Métodos */
public __construct(array|object $array = [], int $flags = 0)
public append(mixed $value): void
public asort(int $flags = SORT_REGULAR): true
public count(): int
public current(): mixed
public getFlags(): int
public key(): string|int|null
public ksort(int $flags = SORT_REGULAR): true
public natcasesort(): true
public natsort(): true
public next(): void
public offsetExists(mixed $key): bool
public offsetGet(mixed $key): mixed
public offsetSet(mixed $key, mixed $value): void
public offsetUnset(mixed $key): void
public rewind(): void
public seek(int $offset): void
public serialize(): string
public setFlags(int $flags): void
public uasort(callable $callback): true
public uksort(callable $callback): true
public unserialize(string $data): void
public valid(): bool
}

Constantes predefinidas

ArrayIterator Flags

ArrayIterator::STD_PROP_LIST

Las propiedades del objeto tienen su funcionalidad normal cuando se accede a ellas como lista (var_dump, foreach, etc.).

ArrayIterator::ARRAY_AS_PROPS

Se puede acceder a las entradas como propiedades (lectura y escritura).

Tabla de contenidos

add a note

User Contributed Notes 4 notes

up
49
Venelin Vulkov
15 years ago
Another fine Iterator from php . You can use it especially when you have to iterate over objects

<?php
$fruits
= array(
"apple" => "yummy",
"orange" => "ah ya, nice",
"grape" => "wow, I love it!",
"plum" => "nah, not me"
);
$obj = new ArrayObject( $fruits );
$it = $obj->getIterator();

// How many items are we iterating over?

echo "Iterating over: " . $obj->count() . " values\n";

// Iterate over the values in the ArrayObject:
while( $it->valid() )
{
echo
$it->key() . "=" . $it->current() . "\n";
$it->next();
}

// The good thing here is that it can be iterated with foreach loop

foreach ($it as $key=>$val)
echo
$key.":".$val."\n";

/* Outputs something like */

Iterating over: 4 values
apple
=yummy
orange
=ah ya, nice
grape
=wow, I love it!
plum=nah, not me

?>

Regards.
up
18
Relakuyae
12 years ago
Need a callback on an iterated value, but don't have PHP 5.4+? This makes is stupid easy:

<?php
class ArrayCallbackIterator extends ArrayIterator {
private
$callback;
public function
__construct($value, $callback) {
parent::__construct($value);
$this->callback = $callback;
}

public function
current() {
$value = parent::current();
return
call_user_func($this->callback, $value);
}
}
?>

You can use it pretty much exactly as the Array Iterator:

<?php
$iterator1
= new ArrayCallbackIterator($valueList, "callback_function");
$iterator2 = new ArrayCallbackIterator($valueList, array($object, "callback_class_method"));
?>
up
10
Sean Burlington
15 years ago
and to iterate recursively use the (sparsely documented) RecursiveArrayIterator

<?php

$fruits
= array(
"apple" => "yummy",
"orange" => "ah ya, nice",
"grape" => "wow, I love it!",
"plum" => "nah, not me"
);

$veg = array("potato" => "chips", "carrot" => "soup");
$grocery = array($fruits, $veg);
$obj = new ArrayObject( $grocery );

$it = new RecursiveIteratorIterator( new RecursiveArrayIterator($grocery));

foreach (
$it as $key=>$val)
echo
$key.":".$val."\n";

?>

Output
--------
apple:yummy
orange:ah ya, nice
grape:wow, I love it!
plum:nah, not me
potato:chips
carrot:soup
up
1
butesa at freenet dot de
1 year ago
The documentation states "This iterator allows to unset and modify values and keys while iterating over Arrays and Objects". But if you pass an array to the constructor, the iterator works with a copy of that array, so the modifications will not be written back to that initial array. ArrayObject behaves the same way.

If you want an iterator that writes back to the array, you can use this function:

<?php
function &getArrayIterator(array &$a): Iterator {
foreach (
$a as $k => &$v) {
yield
$k => $v;
}
}
?>

Usage:

<?php
$array
= [1 => 'a', 2 => 'b'];

$iterator = getArrayIterator($array);
foreach (
$iterator as &$value) {
$value .= 'x';
}

//array(2) {
// [1]=>
// string(2) "ax"
// [2]=>
// &string(2) "bx"
//}
//object(Generator)#4 (0) {
//}
var_dump($array);
var_dump($iterator);

?>

Comparison with plain array, ArrayIterator and ArrayObject:

<?php
$array1
= [1 => 'a', 2 => 'b'];
$array2 = [1 => 'a', 2 => 'b'];
$array3 = [1 => 'a', 2 => 'b'];

foreach (
$array1 as &$value) {
$value .= 'x';
}

$iterator2 = new ArrayIterator($array2);
foreach (
$iterator2 as &$value) {
$value .= 'x';
}

$iterator3 = new ArrayObject($array3);
foreach (
$iterator3 as &$value) {
$value .= 'x';
}

//array(2) {
// [1]=>
// string(2) "ax"
// [2]=>
// string(2) "bx"
//}
var_dump($array1);

//array(2) {
// [1]=>
// string(1) "a"
// [2]=>
// string(1) "b"
//}
//object(ArrayIterator)#1 (1) {
// ["storage":"ArrayIterator":private]=>
// array(2) {
// [1]=>
// string(2) "ax"
// [2]=>
// string(2) "bx"
// }
//}
var_dump($array2);
var_dump($iterator2);

//array(2) {
// [1]=>
// string(1) "a"
// [2]=>
// string(1) "b"
//}
//object(ArrayObject)#2 (1) {
// ["storage":"ArrayObject":private]=>
// array(2) {
// [1]=>
// string(2) "ax"
// [2]=>
// string(2) "bx"
// }
//}
var_dump($array3);
var_dump($iterator3);
?>
To Top