php数组不会对数字求和

Question

why doesn't this code sum my spent_hours for each user?

while ($row = $result->fetch_assoc()) 
{
    $total_spent_time += $row['spent_time'];

    if (!array_key_exists($row['activity_type'], $data)) 
    {
        $data[$row['activity_type']] = array(
            'spent_time' => array('user' => array())
        );

        $data[$row['activity_type']]['spent_time']['user'][$row['user']] = array('time' => $row['spent_time']);

        if (array_key_exists($row['user'], $data[$row['activity_type']]['spent_time']['user'])) 
        {
            $data[$row['activity_type']]['spent_time']['user'][$row['user']]['time'] += $row['spent_time'];
        }
    }

It gives me only the last value of the row.

Answer 1

Try to declare counter before loop:

$total_spent_time = 0;
while ($row = $result->fetch_assoc()) {
    $total_spent_time += $row['spent_time'];
}
echo $total_spent_time;