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ArrayIterator クラス

(PHP 5, PHP 7, PHP 8)

はじめに

このイテレータは、配列やオブジェクトを反復処理する際に 値やキーを修正したり、要素を削除することができます。

同じ配列を何度も反復処理したい場合は、 ArrayObject のインスタンスとそれを参照する ArrayIterator のインスタンスを作成し、 foreach を使用するか getIterator() メソッドを手動でコールします。

クラス概要

class ArrayIterator implements SeekableIterator, ArrayAccess, Serializable, Countable {
/* 定数 */
public const int STD_PROP_LIST;
public const int ARRAY_AS_PROPS;
/* メソッド */
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
}

定義済み定数

ArrayIterator のフラグ

ArrayIterator::STD_PROP_LIST

オブジェクトのプロパティが、 リストとして(var_dump, foreach などから)アクセスされたときの通常の機能を持つ

ArrayIterator::ARRAY_AS_PROPS

エントリがプロパティとしてアクセスできる(読み書きともに)

目次

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User Contributed Notes 4 notes

up
50
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);
?>
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