Online PHP editor | refs for EI4Tn

<?php function merge(array ...$sets) { /** * group contributions by name */ $contributions = array_reduce( $sets, function (array $contributions, array $set) { foreach ($set as $element) { $name = $element['P_Name']; $contribution = $element['Contribution']; if (!array_key_exists($name, $contributions)) { $contributions[$name] = []; } $contributions[$name][] = $contribution; } return $contributions; }, [] ); /** * normalize the array so we remove the name as key, and return a tuple of name and contribution, with the desired * structure */ return array_values(array_map(function (array $contribution, $name) { return [ 'Contribution' => array_sum($contribution), 'P_Name' => $name, ]; }, $contributions, array_keys($contributions))); } $a = [ [ 'Contribution' => 1000, 'P_Name' => 'A', ], [ 'Contribution' => 1500, 'P_Name' => 'B', ], ]; $b = [ [ 'Contribution' => 100, 'P_Name' => 'A', ], [ 'Contribution' => 200, 'P_Name' => 'B', ], ]; $merged = merge($a, $b); var_dump($merged);