How to merge 2 arrays with the same values ​​(and add values)?

Question

PHP

There is an array - pastebin.com/72cWnG8s
Tell me how the elements of the hour and day arrays, if they are repeated (exactly 2, if any of them does not come across, they do not need to be combined).
And with this 2 combined elements add up the sum of the intercations.
I tried crutches, but it doesn’t work out in any way, since the array 1.

Answer 1

Please note that I changed the word intercations to interactions

/**
 *
 * Input array consists of elements as in example
 * <code>
 * ["1072645714669550333_2140738661"]=>
 *  array(3) {
 *  ["hour"]=>
 *  string(2) "23"
 *  ["day"]=>
 *  string(1) "6"
 *  ["interactions"]=>
 *  int(27)
 *}
 *["1071825259138202534_2140738661"]=>
 *  array(3) {
 *  ["hour"]=>
 *  string(2) "20"
 *  ["day"]=>
 *  string(1) "5"
 *  ["interactions"]=>
 *  int(46)
 *}
 * </code>
 * 
 * @param array $array
 *
 * @return array
 */
function addInteractions(array $array){

  $newArray = [];
  foreach($array as $k=>$subarray)//here $k is something like "1071156299686296080_2140738661"
  {
    if( !isset( $newArray[ $subarray['day'] ][ $subarray['hour'] ][ 'interactions' ]) ){
      $newArray[ $subarray['day'] ][ $subarray['hour'] ][ 'interactions' ] = 0;
    }
    $newArray[ $subarray['day'] ][ $subarray['hour'] ][ 'interactions' ] += $subarray['interactions'];

  }
  return $newArray;
}

Answer 2

$all = "";
$all .= $old_array[$i]['hour'];
$all .= $old_array[$i]['day'];
$new_array[] = $all;
$uniq_array = unique(new_array);

Then you can parse back if necessary ...
Do not work with multidimensional arrays, work with the database