Getting largest values from different arrays - php

Question

I want to get the largest values from different arrays. Basically, the arrays are populated from 3 different websites, and I need to know what are the largest tags and photos values of each product.
I have the following array:
$data = array(
'domain1.com' => array(
'id1' => array(
'tags' => '5',
'photos' => '4',
),
'id2' => array(
'tags' => '8',
'photos' => '2',
),
'id3' => array(
'tags' => '6',
'photos' => '1',
),
),
'domain2.com' => array(
'id1' => array(
'tags' => '3',
'photos' => '1',
),
'id2' => array(
'tags' => '4',
'photos' => '9',
),
'id3' => array(
'tags' => '2',
'photos' => '0',
),
),
'domain3.com' => array(
'id1' => array(
'tags' => '7',
'photos' => '3',
),
'id2' => array(
'tags' => '9',
'photos' => '5',
),
'id3' => array(
'tags' => '2',
'photos' => '4',
),
),
);
I need to get the following result:
$data = array(
'id1' => array(
'tags' => '7',
'photos' => '4',
),
'id2' => array(
'tags' => '9',
'photos' => '9',
),
'id3' => array(
'tags' => '6',
'photos' => '4',
),
);

Answer 1

This is solveable with a simple loop:
$new = array();
foreach($data as $domain){
foreach($domain as $id => $_data){
foreach($_data as $elem => $value) {
if(!isset($new[$id][$elem]) || $value > $new[$id][$elem]){
$new[$id][$elem] = $value;
}
}
}
}
Which returns:
Array
(
[id1] => Array
(
[tags] => 7
[photos] => 4
)
[id2] => Array
(
[tags] => 9
[photos] => 9
)
[id3] => Array
(
[tags] => 6
[photos] => 4
)
)
Example

Answer 2

The easiest way is to use nested foreach loops to iterate and capture the data. The results are updated if there is a higher value found in the results array.
$results = [];
foreach ($data as $domain => $items) {
foreach ($items as $id => $elements) {
if (!isset($results[ $id ])) {
$results[ $id ] = [];
}
foreach ($elements as $tag => $value) {
if (!isset($results[ $id ][ $tag ]) || $value>$results[ $id ][ $tag ]) {
$results[ $id ][ $tag ] = $value;
}
}
}
}
print_r($results);