Remove Parent in PHP Multidimensional Array - php

Question

What's the best way to remove the parent of a matched key in an Multidimensional Array? For example, let's assume we have the following array and I want to find "[text] = a" and then delete its parent array [0]...
(array) Array
(
[0] => Array
(
[text] => a
[height] => 30
)
[1] => Array
(
[text] => k
[height] => 30
)
)

Answer 1

Here’s the obvious:
foreach ($array as $key => $item) {
if ($item['text'] === 'a') {
unset($array[$key]);
}
}

Answer 2

using array_filter:
function filter_callback($v) {
return !isset($v['text']) || $v['text'] !== 'a';
}
$array = array_filter($array, 'filter_callback');
this will only leave 'parent elements' in the array where text != a, therefore deleting those where text equals a

Answer 3

The inner arrays don't maintain any reference to their "parent" arrays, so you'd have to write a function to manually track this. Something like this might work:
function searchAndDestroy(&$arr, $needle) {
foreach ($arr as &$item) {
if (is_array($item)) {
if (searchAndDestroy($item, $needle)) {
return true;
}
} else if ($item === $needle) {
$item = null;
return true;
}
}
}
Note that this is designed to work at any level of nesting, not just two dimensions, so it might be a bit of overkill if you only need it for situations like in your example.

Answer 4

A simple and safe solution(I'd not remove/unset elements from an array I'm looping through) could be:
$new_array = array();
foreach($array as $item)
{
if($item['text'] != "a")
{
$new_array[] = $item;
}
}

Answer 5

My implementation:
function searchAndDestroy(&$a, $key, $val){
foreach($a as $k => &$v){
if(is_array($v)){
$r = searchAndDestroy(&$v, $key, $val);
if($r){
unset($a[$k]);
}
}elseif($key == $k && $val == $v){
return true;
}
}
return false;
}
searchAndDestroy($arr, 'text', 'a');
To test it:
<pre><?php
function searchAndDestroy(&$a, $key, $val){
foreach($a as $k => &$v){
if(is_array($v)){
$r = searchAndDestroy(&$v, $key, $val);
if($r){
unset($a[$k]);
}
}elseif($key == $k && $val == $v){
return true;
}
}
return false;
}
$arr = array(array('text'=>'a','height'=>'30'),array('text'=>'k','height'=>array('text'=>'a','height'=>'20')));
var_dump($arr);
searchAndDestroy($arr, 'text', 'a');
var_dump($arr);
?></pre>
This function does it recursively.