Loop through multi-dimensional array and remove duplicate and merge other values - php

Question

I have array like below. I want to unset all array having same q_id but merge its name key.
array
0 =>
array
'field_name' => string 'Hindu rastrya' (length=13)
'name' => string '283' (length=3)
'q_id' => string '199' (length=3)
1 =>
array
'field_name' => string 'dharma nirpachya' (length=16)
'name' => string '284' (length=3)
'q_id' => string '199' (length=3)
2 =>
array
'field_name' => string 'j vaye pni hunxa' (length=16)
'name' => string '285' (length=3)
'q_id' => string '199' (length=3)
3 =>
array
'field_name' => string 'Nepal' (length=5)
'name' => string '286' (length=3)
'q_id' => string '200' (length=3)
4 =>
array
'field_name' => string 'India' (length=5)
'name' => string '287' (length=3)
'q_id' => string '200' (length=3)
5 =>
array
'field_name' => string 'China' (length=5)
'name' => string '288' (length=3)
'q_id' => string '200' (length=3)
Expected:
array
0 =>
array
'field_name' => string 'Hindu rastrya' (length=13)
'name' =>
array
0 => string '283' (length=3)
1 => string '284' (length=3)
2 => string '285' (length=3)
'q_id' => string '199' (length=3)
1 =>
array
'field_name' => string 'Nepal' (length=16)
'name' =>
array
0 => string '286' (length=3)
1 => string '287' (length=3)
2 => string '288' (length=3)
'q_id' => string '200' (length=3)
I tried following code but It didnot preserve the keys so it fails:
foreach ($form_option_data as $key=>$option)
{
if($form_option_data[$key]['q_id'] == $form_option_data[$key+1]['q_id']){
unset($form_option_data[$key+1]);
}
}

Answer 1

The following should do the job:
$data = ...; //initial array
$result = array();
foreach ($data as $entry) {
if (!array_key_exists($entry['q_id'], $result)) {
$result[$entry['q_id']] = array(
'q_id' => $entry['q_id'],
'name' => array($entry['name'])
);
} else {
$result[$entry['q_id']]['name'][] = $entry['name'];
}
}
$result = array_values($result); // to re-index the table so that keys start from 0