Add more values to same key using foreach - php

Question

So I have array like this one:
[
(int) 0 => [
'user_id' => (int) 20098238,
'location_id' => (int) 20014727
],
(int) 1 => [
'user_id' => (int) 20098238,
'location_id' => (int) 20027167
],
(int) 2 => [
'user_id' => (int) 20098238,
'location_id' => (int) 20027168
],
(int) 3 => [
'user_id' => (int) 20098238,
'location_id' => (int) 20027169
],
(int) 4 => [
'user_id' => (int) 20011189,
'location_id' => (int) 20012490
],
(int) 5 => [
'user_id' => (int) 20011189,
'location_id' => (int) 20016161
],
(int) 6 => [
'user_id' => (int) 20011189,
'location_id' => (int) 20018679
],
(int) 7 => [
'user_id' => (int) 20011189,
'location_id' => (int) 20023569
],
(int) 8 => [
'user_id' => (int) 20102015,
'location_id' => (int) 20008315
],
(int) 9 => [
'user_id' => (int) 20102015,
'location_id' => (int) 20008689
],
(int) 10 => [
'user_id' => (int) 20102015,
'location_id' => (int) 20021267
]
]
I want to get this as restult array like this one
[
(int) 20098238 => [
(int) 0 => (int) 20014727,
(int) 1 => (int) 20027167,
(int) 2 => (int) 20027168,
(int) 3 => (int) 20027169
],
(int) 20011189 => [
(int) 0 => (int) 20012490,
(int) 1 => (int) 20016161,
(int) 2 => (int) 20018679,
(int) 3 => (int) 20023569
],
(int) 20102015 => [
(int) 0 => (int) 20008315,
(int) 1 => (int) 20008689,
(int) 2 => (int) 20021267
]
]
Here is my code, but I am getting only part of sorting
$customerData = [];
foreach ($userIds as $data) {
$i = 0;
foreach ($customerData as $k => $check) {
if ($k == $data['user_id']) {
$customerData[$k][$i] = $data['location_id'];
}
$i++;
}
$customerData[$data['user_id']][$i] = $data['location_id'];
}
As result this code make key like user_id but there is problem with pushing array for that key. I am getting always maximal 2 locations per key.
Thank you for helping!

Answer 1

Your Perfect Solution is here :
$customerData = [];
foreach ($userIds as $data) {
foreach ($customerData as $k => $check) {
if ($k == $data['user_id'] && $data['location_id'] == $check) {
$customerData[$k][] = $data['location_id'];
}
}
$customerData[$data['user_id']][] = $data['location_id'];
}
Live Demo

Answer 2

Simply remove the $i usage and use $customerData[$k][] in your loop. This will add a new occurance to the userid array automatically and as many as exist.
$customerData = [];
foreach ($userIds as $data) {
foreach ($customerData as $k => $check) {
$customerData[$k][] = $data['location_id'];
}
}