PHP combine array based on value of particular element - php

Question

I have an array that looks like this
Array (
[0] => Array
(
[id] => 123
[count] => 1
)
[1] => Array
(
[id] => 123
[count] => 3
)
[2] => Array
(
[id] => 513
[count] => 0
)
[3] => Array
(
[id] => 561
[count] => 1
)
[4] => Array
(
[id] => 613
[count] => 7
)
)
What I want to do is create a new array, that totals the count where the id values are the same. So for example, the new array would look like this:
Array (
[0] => Array
(
[id] => 123
[count] => 4
)
[1] => Array
(
[id] => 513
[count] => 0
)
[2] => Array
(
[id] => 561
[count] => 1
)
[3] => Array
(
[id] => 613
[count] => 7
)
)
Would anyone know a good method to do this?
Thank you!

Answer 1

Short and simple:
$new_array = array();
foreach($data_array as $value) {
if(array_key_exists($value['id'], $new_array)) {
$new_array[$value['id']] += $value['count'];
} else {
$new_array[$value['id']] = $value['count'];
}
}
echo print_r($new_array,true);
I made it id => value since there didn't seem to need another array for data when the id could be used as the array's key.

Answer 2

Any reason why you are not making an associative array of id => count

Answer 3

You can do it with the following function (I didn't tested the code, but it should work ):
function get_count_array($arr) {
$new_array = array();
foreach($arr as $item) {
$found = false;
//loop through all the current new items to check if we already have it
for($i = 0; $i < count($new_array); $i++) {
//do we have it?
if($new_array[$i]['id'] == $item['id']) {
$new_array[$i]['count'] += 1;
$found = true;
break;
}
}
if(!$found) {
$new_array[] = array('id' => $item['id'], 'count' => 0);
}
}
return $new_array;
}