How to merge an array with child elements - php

Question

I have an array with same customerid. I want to merge all same customerid arrays in to one with few amends to the array.
Array
(
[0] => Array
(
[customerid] => 13
[customer_fullname] => Chris
[profession_id] => 8
[profession_name] => Producer
)
[1] => Array
(
[customerid] => 1
[customer_fullname] => John
[profession_id] => 8
[profession_name] => Producer
)
[2] => Array
(
[customerid] => 13
[customer_fullname] => Chris
[profession_id] => 7
[profession_name] => Camera
)
)
So now I want a new array to be created like this:
Array(
[customerid] => 13
[customer_fullname] => Chris
[new_array] => array(
[0]=>[profession_id] => 8, [profession_name] => Producer,
[1]=>[profession_id] => 7, [profession_name] => Camera
)
)
Spent some time on it but wasn't able to get it right

Answer 1

There are better approaches if you're merging lots of records, but if you want a way to just merge two records as stated, I'd just do this:
$array1 = array(
'customerid' => 13
'customer_fullname' => 'John',
'profession_id' => 8,
'profession_name' => 'Producer'
);
$array2 = array(
'customerid' => 13
'customer_fullname' => 'John',
'profession_id' => 7,
'profession_name' => 'Director'
);
function merge_customers($customerA, $customerB)
{
$newCustomer = array();
if ($customerA['customerid'] == $customerB['customerid'])
{
$newCustomer['customerid'] = $customerA['customerid'];
$newCustomer['customer_fullname'] = $customerA['customer_fullname'];
$newCustomer['new_array'] = array(
array(
'profession_id' => $customerA['profession_id'],
'profession_name' => $customerA['profession_name']
),
array(
'profession_id' => $customerB['profession_id'],
'profession_name' => $customerB['profession_name']
)
);
return $newCustomer;
}
/* We can't merge these if they're different customers. */
return NULL;
}

Answer 2

The extended solution which is also well-suited for finding and "merging" multiple groups of entries which has same customerid. Used functions: array_filter, array_count_values, array_keys, array_walk, array_chunk and array_values:
// supposing $arr is your initial array
// finds which 'customerid' has multiple entries
$dupIds = array_filter(array_count_values(array_column($arr, "customerid")), function($v) {
return $v > 1;
});
$dupIds = array_keys($dupIds);
$result = [];
array_walk($arr, function($v) use(&$result, $dupIds) {
if (in_array($v['customerid'], $dupIds)) {
$parts = array_chunk($v, 2, true);
if (!isset($result[$v['customerid']])) {
$result[$v['customerid']] = $parts[0] + ['new_array' => [$parts[1]]];
} else {
$result[$v['customerid']]['new_array'][] = $parts[1];
}
}
});
print_r(array_values($result));
The output:
Array
(
[0] => Array
(
[customerid] => 13
[customer_fullname] => Chris
[new_array] => Array
(
[0] => Array
(
[profession_id] => 8
[profession_name] => Producer
)
[1] => Array
(
[profession_id] => 7
[profession_name] => Camera
)
)
)
)

Answer 3

Quick hack, maybe there is a nicer solution.
Note: The second "for each" loop is only needed if there is the possibility that the arrays don't have the same fields.
function merge($array1, $array2){
$result = array();
foreach($array1 as $key => $value){
if(isset($array2[$key]) && $array2[$key]!=$array1[$key]){
$result[$key][]=$value;
$result[$key][]=$array2[$key];
}else{
$result[$key]=$value;
}
}
foreach($array2 as $key => $value){
if(!isset($result[$key])){
$result[$key] = $value;
}
}
return $result;
}
print_r(merge($array1, $array2));