Sum the elements of a field in a array with predefined fields

array_sum.php

<?php

// Log of players result
$dataArray = array(
    array('player' => 'John', 'day' => '1', 'points' => 230),
    array('player' => 'Hans', 'day' => '1', 'points' => 300),
    array('player' => 'Karl', 'day' => '1', 'points' => 200),

    array('player' => 'John', 'day' => '1', 'points' => 250),
    array('player' => 'Hans', 'day' => '1', 'points' => 300),
    array('player' => 'Karl', 'day' => '1', 'points' => 190),

    array('player' => 'John', 'day' => '2', 'points' => 200),
    array('player' => 'Hans', 'day' => '2', 'points' => 330),
    array('player' => 'Karl', 'day' => '2', 'points' => 250),

    array('player' => 'John', 'day' => '2', 'points' => 300),
    array('player' => 'Hans', 'day' => '2', 'points' => 200),

    array('player' => 'Karl', 'day' => '3', 'points' => 220),
);

// Objective: sum the points of the each players in each day
$newDataArray = array();

foreach($dataArray as $node) {
    $hashContent = array(
        $node['player'],
        // $node['day'], // Uncomment to see the new result
    );

    $hash = hash('md5', implode('--', $hashContent));

    if (isset($newDataArray[$hash])) {
        $newDataArray[$hash]['points'] += $node['points'];
    } else {
        $newDataArray[$hash] = $node;
    }
}

var_dump($newDataArray);