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!
La clase RecursiveArrayIterator
(PHP 5 >= 5.1.0, PHP 7, PHP 8)
Introducción
Este iterador permite destruir y modificar valores y claves mientras se iteran arrays y objetos de la misma manera que con ArrayIterator. Adicionalmente es posible iterar la entrada del iterador actual.
Sinopsis de la Clase
/* Constantaes heredadas constants */
/* Constantes */
/* Métodos */
/* Métodos heredados */
}Constantes predefinidas
RecursiveArrayIterator Flags
RecursiveArrayIterator::CHILD_ARRAYS_ONLY-
Trata sólo los array (no objetos) como si tuvieran hijos para la itaración recursiva.
Tabla de contenidos
- RecursiveArrayIterator::getChildren — Devuelve un iterador para la entrada actual si este es un array o un object
- RecursiveArrayIterator::hasChildren — Devuelve si la entrada actual es un array o un objeto
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User Contributed Notes 4 notes
c dot 1 at smithies dot org ¶
13 years ago
mccarthy dot richard at gmail dot com ¶
13 years ago
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
lemoinem dot remove at me dot mlemoine dot name ¶
10 years ago
The RecursiveArrayOnlyIterator behaviour c dot 1 at smithies dot org presented can also be achieved using the (undocumented) flag RecursiveArrayIterator::CHILD_ARRAYS_ONLY (https://github.com/php/php-src/blob/master/ext/spl/spl_array.c#L1970 and https://github.com/php/php-src/blob/master/ext/spl/spl_array.c#L1620)
Edgar ¶
2 years ago
<?php
$array = [
'A','B',
'C'=>[
'D','E',
'F'=>['G','H']
],
'I','J'
];
$iterator = new RecursiveArrayIterator($array);
foreach($iterator as $key=>$value)
{
echo $key,':', $value,'<br>';
}
/**
Output
0:A
1:B
C:Array
2:I
3:J
*/
//-------------
//Recursive...
$array = [
'A','B',
'C'=>[
'D','E',
'F'=>['G','H']
],
'I','J'
];
$it = new RecursiveArrayIterator($array);
$iterator = new RecursiveIteratorIterator($it);
foreach($iterator as $key=>$value)
{
echo $key,':', $value,'<br>';
}
/**
Output
0:A
1:B
0:D
1:E
0:G
1:H
2:I
3:J
*/
?>
