Merge arrays together based on different values - php

Question

I am having trouble thinking of the logic with the following problem:
I have the following array (has been snipped, as its much larger)
Array
(
[0] => Array
(
[code] => LAD001
[whqc] => GEN
[stocktag] => NONE
[qty] => 54
)
[1] => Array
(
[code] => LAD001
[whqc] => GEN
[stocktag] => NONE
[qty] => 6
)
[2] => Array
(
[code] => LAD004
[whqc] => HOLD
[stocktag] => NONE
[qty] => 6
)
)
I basically need to comebine all the keys in this array so that where the code, whqc and stocktag are the same, add the qty values together. With the example below, I need to end up with this:
Array
(
[0] => Array
(
[code] => LAD001
[whqc] => GEN
[stocktag] => NONE
[qty] => 60
)
[1] => Array
(
[code] => LAD004
[whqc] => HOLD
[stocktag] => NONE
[qty] => 6
)
)
As the first and second keys of the array had the same code, whqc and stocktag, the qty's have been added together into the one key.
Any ideas?

Answer 1

I would suggest combining the group values in to a hash, storing the full array under the hash as a key and if you have a duplicate, add the quantity, then do array_values() to pull the results.
$aggregated = array();
foreach ($records as $cRec) {
// The separator | has been used, if that appears in the tags, change it
$cKey = md5($cRec['code'] . '|' . $cRec['whqc'] . '|' . $cRec['stocktag']);
if (array_key_exists($cKey, $aggregated)) {
$aggregated[$cKey]['qty'] += $cRec['qty'];
} else {
$aggregated[$cKey] = $cRec;
}
}
// Reset the keys to numerics
$aggregated = array_values($aggregated);

Answer 2

I would try something like:
$output = array();
foreach($array as $details){
//make distinct key
$key = $details['code'].'_'.$details['whqc'];
if(!isset($output[$key])){
$output[$key] = $details;
}else{
$output[$key]['qty'] += $details['qty'];
$output[$key]['stocktag'] = $details['stocktag'];
}
}
$output = array_values($output);
print_r($output);
update: Orbling was first ;-)