Php Convert Multidimensional array to string - php

Question

Below is my function:
public function getChildrenId(){
$child_id = array($this->db->query("SELECT customer_id
FROM " . DB_PREFIX . "customer
WHERE parent IN ( " .(int)$this->customer->getId().") "));
foreach($child_id as $id =>$value) {
$conv = json_decode(json_encode($value), true);
$final = array_slice($conv,2);
foreach ($final as $gchildren => $key) {
sort($key);
$gr = array_slice($key,0,$this->INF);
}
}
return $gr;
}
It outputs:
array (size=3)
0 =>
array (size=1)
'customer_id' => string '2' (length=1)
1 =>
array (size=1)
'customer_id' => string '4' (length=1)
2 =>
array (size=1)
'customer_id' => string '7' (length=1)
I am trying to get the values of the nested arrays. When I use foreach I only get data from array[0]. I also tried slicing the parent array and still didn't get it right, it outputs array,array,array.
I would like to extract these arrays values to a new array that I can use to query the database. final_array = array (2,4,7).
Thank you in advance!

Answer 1

If your array looks like this, then the foreach should create the array your looking for.
array (size=3)
0 =>
array (size=1)
'customer_id' => string '2' (length=1)
1 =>
array (size=1)
'customer_id' => string '4' (length=1)
2 =>
array (size=1)
'customer_id' => string '7' (length=1)
The following php will output array(2,4,7);
<?php
$aNewArray = array();
foreach($aArray as $aArray){
$aNewArray[] = $aArray['customer_id'];
}
var_dump($aNewArray);
?>
You dont need a multidimensional array for this though.