For gurus: bug in php? Recursive foreach dont work properly.

Question posted by: Tamagafk (Guest) on April 12th, 2007 09:05 AM

Hi! Looks like there is a bug in php. If I have function which uses
foreach to run trough array recursively, the lop-level foreach
interupted by lover-level foreach'es. If I use simply 'for' everything
is ok. Example:

I have an array of 3 objects connected hierarchically by their
variables id and parentId, here is the hierarchy:
id=1 parentId=0
....id=2 parentId=1
....id=3 parentId=1

I start digging from item with id=1 down to its chils and top-level
foreach NEVER REACH ELEMENT 3!!! Top-level foreach just stops.

<?php
function prn($s){
echo($s.'<br>');
}

$nodes = array();
$nodes[0] = new node(1, 0);
$nodes[1] = new node(2, 1);
$nodes[2] = new node(3, 1);
$nodes[3] = new node(4, 0);

class node{
var $id;
var $parentId;

function node($id, $parentId){
$this->id = $id;
$this->parentId = $parentId;
}

function dig($level){
global $nodes;

$l = '';
for($i=0; $i<$level; $i++) $l.='..';
prn($l.'looking for childs of '.$this->id.' {');

foreach($nodes as $n){
prn($l.$n->id.' (parent '.$n->parentId.')');
if($n->parentId == $this->id){
$n->dig($level+1);
}
}

prn($l.'}');
}

}

$nodes[0]->dig(0);

?>

The output should look like this:

looking for childs of 1 {
1 (parent 0)
2 (parent 1)
...looking for childs of 2 {
...1 (parent 0)
...2 (parent 1)
...3 (parent 1)
...}
3 (parent 1)
...looking for childs of 3 {
...1 (parent 0)
...2 (parent 1)
...3 (parent 1)
...}
}

But it looks like this:

looking for childs of 1 {
1 (parent 0)
2 (parent 1)
...looking for childs of 2 {
...1 (parent 0)
...2 (parent 1)
...3 (parent 1)
...}
}

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