PHP Array custom fusion of values - php

Question

Good morning!
I'm using a SQL query to get category IDs from posts. Several post can have the same ID if they are from the same category. This is my array:
Array (
[0] => stdClass Object ( [catid] => 48 )
[1] => stdClass Object ( [catid] => 77 )
[2] => stdClass Object ( [catid] => 57 )
[3] => stdClass Object ( [catid] => 57 )
[4] => stdClass Object ( [catid] => 38 ))
Now I need to get the sum of all different catid's (in this case 4). I could achieve this by using "distinct" or a "group by" in my SQL, anyway I didnt because they mess up my results.
The problem is, that some catids should be replaced. For example is catid 48 'HDDs' and 77 is 'Storage' so 48 should be a part of 77 (So the sum is now 3). I already got an array of the catids that should be merged:
$catMergeArray = array(
38=>74,36=>46,34=>72,37=>73,40=>76,39=>75,103=>85,102=>81,53=>82,51=>80,50=>79,
55=>90,56=>91,57=>92,58=>93,55=>90,104=>68,106=>69,65=>70,66=>86,108=>95,48=>77,
172=>171,105=>170,111=>169);
by using
foreach ($result as $cats) {
$newarray[] = $cats->catid;
}
I changed my Array to
$newarray = Array ([0] => 48 [1] => 77 [2] => 57 [3] => 57 [4] => 38)
Then (like mentioned in $catMergeArray where it says 48=>77) remove the [0] => 48 value so the result should be $catids = Array ([0] => 77 [1] => 57 [2] => 38) so I can count the elements and have 3 as result to work with.

Answer 1

ummm have you tried using array_unique? http://php.net/manual/en/function.array-unique.php
or you can also group them into a unique array index like this:
$summary = array();
foreach( $catids as $catid => $cat){
$summary[$catid][] = $cat;
}

Answer 2

It'd probably be better to do it in php. Here's a rough idea and some pseudocode.
probably not very efficent nor elegent, but it should work.
$list_of_id = mysqli_fetch_array(query("distinct catId"));
for($i=0;$i<count($list_of_id);$i++){
$parent_cat_id = $catMergeArray[$list_od_id[$i]];
if ($parent_cat_id > 0){
for($j=0;$j<count($list_of_id);$j++){
if($list_of_id[$j]==$parent_cat_id){
unset($list_of_id[$i]);
break;
}
}
}
}
echo count($list_of_id);
EDIT: since OP doesn't seems to understand pseudocode...I'll make a php version... Surely it's clear enough?

Answer 3

Thanks for all the help. I now solved my problem with this:
foreach ($result as $value) {
$intArray[] = $value->catid;
}
$uniqueArray = array_unique($intArray);
$cUniqueArray = count($uniqueArray);
$cma = array(48=>77);
$lenght = $cUniqueArray-1;
for($i = 0; $i <= $lenght; $i++){
$key = array_search($uniqueArray[$i],$cma);
if(is_int($key)){
$uniqueArray[$i] = $key;
}
}