A classe ArrayIterator

(PHP 5, PHP 7, PHP 8)

Introdução

Este iterator permite remover e modificar valores e chaves quando iterando arrays e objetos.

Quando você quiser iterar o mesmo array múltiplas vezes você precisa instanciar ArrayObject e criar instâncias de ArrayIterator que é consultado usando foreach ou chamando o método getIterator() diretamente.

Sinopse da classe

class ArrayIterator implements ArrayAccess, SeekableIterator, Countable, Serializable {

/* Constantes */

const integer STD_PROP_LIST = 1;

const integer ARRAY_AS_PROPS = 2;

/* Métodos */

public append(mixed $value): void

public asort(int $flags = SORT_REGULAR): true

public count(): int

public current(): mixed

public getArrayCopy(): array

public getFlags(): void

key(): mixed

public ksort(int $flags = SORT_REGULAR): true

public natcasesort(): true

public natsort(): true

next(): void

public offsetExists(mixed $key): bool

public offsetGet(mixed $key): mixed

public offsetSet(mixed $key, mixed $value): void

public offsetUnset(mixed $key): void

rewind(): void

seek(int $position): void

public serialize(): string

public setFlags(string $flags): void

public uasort(callable $callback): true

public uksort(callable $callback): true

public unserialize(string $data): void

valid(): bool

}

Constantes pré-definidas

Flags

ArrayIterator::STD_PROP_LIST: Propriedades do objeto mantém sua funcionalidade normal quando acessadas como lista (var_dump, foreach, etc.).
ArrayIterator::ARRAY_AS_PROPS: Elementos podem ser acessados como propriedades (leitura e escrita).

Índice

ArrayIterator::append — Append an element
ArrayIterator::asort — Sort entries by values
ArrayIterator::__construct — Construct an ArrayIterator
ArrayIterator::count — Conta os elementos
ArrayIterator::current — Retorna o valor do elemento atual do array
ArrayIterator::getArrayCopy — Get array copy
ArrayIterator::getFlags — Retorna as flags de comportamento
ArrayIterator::key — Retorna a chave do elemento atual do array
ArrayIterator::ksort — Sort entries by keys
ArrayIterator::natcasesort — Sort entries naturally, case insensitive
ArrayIterator::natsort — Sort entries naturally
ArrayIterator::next — Avança para o próximo elemento
ArrayIterator::offsetExists — Check if offset exists
ArrayIterator::offsetGet — Get value for an offset
ArrayIterator::offsetSet — Set value for an offset
ArrayIterator::offsetUnset — Unset value for an offset
ArrayIterator::rewind — Recoloca o array no início
ArrayIterator::seek — Aponta para determinada posição
ArrayIterator::serialize — Serialize
ArrayIterator::setFlags — Define as flags que irão alterar o comportamento
ArrayIterator::uasort — Sort with a user-defined comparison function and maintain index association
ArrayIterator::uksort — Sort by keys using a user-defined comparison function
ArrayIterator::unserialize — Unserialize
ArrayIterator::valid — Verifica se o array possui mais elementos

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User Contributed Notes 7 notes

down

Venelin Vulkov ¶

14 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.

down

Relakuyae ¶

11 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"));

?>

down

butesa at freenet dot de ¶

7 months 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);
?>

down

Sean Burlington ¶

14 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

down

shaman_master at list dot ru ¶

3 years ago


If you want something like `ArrayCallbackIterator` by Relakuyae https://www.php.net/manual/ru/class.arrayiterator.php#106231 , use function `iterator_apply`.

down

-8

daniel dot rutkoski at gmail dot com ¶

7 years ago


<?php
class PrintArray
{
    private $code = null;

    function __construct ($val)
    {
        $this->code = $val;
        $this->_print();
    }
    
    private function arrayIterator($val, $grau)
    {
        $grau++;
        $arr = new \ArrayIterator($val);
        while ($arr->valid())
        {
            if(is_array($arr->current()))
            {
                $this->arrayIterator($arr->current(), $grau);
            }
            else
            {
                $this->code .= str_repeat(" ", (4 * $grau)) . $arr->key() . " : " . $arr->current() . PHP_EOL;
            }
            $arr->next();
        }
    }
    
    private function _print() 
    {
        if (is_array($this->code))
        {
            $arr = new \ArrayIterator($this->code);
            $this->code = 'array(' . PHP_EOL;
            while ($arr->valid())
            {
                if(is_array($arr->current()))
                {
                    $this->arrayIterator($arr->current(), 0);
                }
                else
                {
                    $this->code .= $arr->key() . " : " . $arr->current() . "\n";
                }
                $arr->next();
            }
            $this->code .= ')';
        }
        return $this;
    }
    
    public function getVal ()
    {
        return $this->code;
    }
}

$arr = array(
    array(
        'ok' => 1, array(9,7,5,9,'a','b'=>array(1,2)),
        'error' => 2, array('h','u','o')
    )
    , 'array'
);
$pArray = new PrintArray($arr);
var_dump($pArray->getVal());

down

-27

foobuilder at gmail dot com ¶

12 years ago


Unsetting all keys of an ArrayItem within foreach will always leave the second key: 

<?php
$items = new ArrayObject(range(0, 9)); 

while (list($k, $v) = each($items)) {
    unset($items[$k]); 
}

print_r($items); 

//  ArrayIterator Object
//  (
//      [storage:ArrayIterator:private] => Array
//          (
//              [1] => 1
//          )
//  )
?>

I'm not sure if this is a bug as unsetting keys within foreach is usually a bad idea to begin with (use while instead), but it's something to be aware of.

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