AppendIterator::key

<?php
$array_a = new ArrayIterator(array('a' => 'aardwolf', 'b' => 'bear', 'c' => 'capybara'));
$array_b = new ArrayIterator(array('apple', 'orange', 'lemon'));

$iterator = new AppendIterator;
$iterator->append($array_a);
$iterator->append($array_b);

// Manual iteration
$iterator->rewind();
while ($iterator->valid()) {
    echo $iterator->key() . ' ' . $iterator->current() . PHP_EOL;
    $iterator->next();
}

echo PHP_EOL;

// With foreach
foreach ($iterator as $key => $current) {
    echo $key . ' ' . $current . PHP_EOL;
}
?>

a aardwolf
b bear
c capybara
0 apple
1 orange
2 lemon

a aardwolf
b bear
c capybara
0 apple
1 orange
2 lemon