Morteza Negahi Morteza Negahi - 1 month ago 21
PHP Question

How to convert three array to flat array?

I have a three array and I need to marge or convert to flat array but i can't.

I create tree with this code.

$fakepages = array();
$fakepages[0] = array('id' => 1, 'parent_id' => 0, 'title' => 'Parent Page');
$fakepages[1] = array('id' => 2, 'parent_id' => 1, 'title' => 'Sub Page');
$fakepages[2] = array('id' => 3, 'parent_id' => 2, 'title' => 'Sub Sub Page');
$fakepages[3] = array('id' => 4, 'parent_id' => 3, 'title' => 'Another Parent Page');
$fakepages[4] = array('id' => 5, 'parent_id' => 0, 'title' => 'Another Parent Page 5');
$fakepages[5] = array('id' => 6, 'parent_id' => 2, 'title' => 'Another Parent Page 5');

$tree = $this->buildTree($fakepages);
return $tree;

private function buildTree(array $elements, $parentId = 0) {
$branch = array();

foreach ($elements as $element) {
if ($element['parent_id'] == $parentId) {
$children = $this->buildTree($elements, $element['id']);
if ($children) {
$element['children'] = $children;
}
$branch[] = $element;
}
}

return $branch;
}


and this is my sort or marge or anything code . whats my code problem how can i fix this and make the left picture?
private function findchild($trees)
{
$arr = array();

foreach ($trees as $tree) {

if (isset($tree['children'])) {
$this->mes[] = ['id'=>$tree['id'],'parent_id'=>$tree['parent_id']];
$arr[] = $this->findchild($tree['children']);
}
else{
$this->mes[] = ['id'=>$tree['id'],'parent_id'=>$tree['parent_id']];
$arr[] = $tree;
}
return $arr;
}
}
private $mes = [];


i have right part need convert to left part
enter image description here

Answer

You could use this PHP function, which assumes your data is an array of standard class objects:

function flatten($arr) {
    $result = [];
    foreach($arr as $item) {
        if (isset($item->children))
            $result = array_merge($result, flatten($item->children));
        unset($item->children);
        $result[] = $item;  
    }
    return $result;
}

Of course, if your original value is JSON, you need to first decode it and only then pass it to this function, like this:

$arr = json_decode($json);
// Flatten it
$arr = flatten($arr);
// Optionally sort the result
usort($arr, function($a, $b) { return $a->id - $b->id; });

See it run on eval.in

If your data consists of associative arrays (not "objects"), then, the code needs to use bracket notation instead of ->:

function flatten($arr) {
    $result = [];
    foreach($arr as $item) {
        if (isset($item['children']))
            $result = array_merge($result, flatten($item['children']));
        unset($item['children']);
        $result[] = $item;
    }
    return $result;
}

and the sort:

usort($arr, function($a, $b) { return $a['id'] - $b['id']; });
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