ParentIterator::rewind
If you are iterating over a multi-dimensional array of objects, you may be tempted to use a RecursiveArrayIterator within a RecursiveIteratorIterator. You are likely to get baffling results if you do. That is because RecursiveArrayIterator treats all objects as having children, and tries to recurse into them. But if you are interested in having your RecursiveIteratorIterator return the objects in your multi-dimensional array, then you don't want the default setting LEAVES_ONLY, because no object can be a leaf (= has no children).
The solution is to extend the RecursiveArrayIterator class and override the hasChildren method appropriately. Something like the following might be suitable:
<?php
class RecursiveArrayOnlyIterator extends RecursiveArrayIterator {
public function hasChildren() {
return is_array($this->current());
}
}
?>
Of course, this simple example will not recurse into ArrayObjects either!
RecursiveArrayIterator クラス
(PHP 5 >= 5.1.0)
導入
このイテレータは、ArrayIterator と同じように配列やオブジェクトを反復処理しつつ、 そのキーや値を消去したり書き換えたりすることができます。 さらに、現在のイテレータのエントリを反復処理することも可能です。
クラス概要
/* メソッド */
/* Inherits */
}目次
- RecursiveArrayIterator::getChildren — 現在のエントリが配列あるいはオブジェクトである場合に、そのイテレータを返す
- RecursiveArrayIterator::hasChildren — 現在のエントリが配列あるいはオブジェクトであるかどうかを返す
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User Contributed Notes
RecursiveArrayIterator
c dot 1 at smithies dot org
15-Nov-2011 10:29
mccarthy dot richard at gmail dot com
22-Feb-2011 07:23
Using the RecursiveArrayIterator to traverse an unknown amount of sub arrays within the outer array. Note: This functionality is already provided by using the RecursiveIteratorIterator but is useful in understanding how to use the iterator when using for the first time as all the terminology does get rather confusing at first sight of SPL!
<?php
$myArray = array(
0 => 'a',
1 => array('subA','subB',array(0 => 'subsubA', 1 => 'subsubB', 2 => array(0 => 'deepA', 1 => 'deepB'))),
2 => 'b',
3 => array('subA','subB','subC'),
4 => 'c'
);
$iterator = new RecursiveArrayIterator($myArray);
iterator_apply($iterator, 'traverseStructure', array($iterator));
function traverseStructure($iterator) {
while ( $iterator -> valid() ) {
if ( $iterator -> hasChildren() ) {
traverseStructure($iterator -> getChildren());
}
else {
echo $iterator -> key() . ' : ' . $iterator -> current() .PHP_EOL;
}
$iterator -> next();
}
}
?>
The output from which is:
0 : a
0 : subA
1 : subB
0 : subsubA
1 : subsubB
0 : deepA
1 : deepB
2 : b
0 : subA
1 : subB
2 : subC
4 : c