PHP Ассоциативный массив, как отфильтровать по величине значений?
Как вариант$arr = [['name' => 'ford', 'count' => 2],
    ['name' => 'ford', 'count' => 8],
    ['name' => 'lada', 'count' => 9],
    ['name' => 'lada', 'count' => 2]];

$result = [];
foreach($arr as $car) {
    if (!isset($result[$car['name']]) || $result[$car['name']] < $car['count']) {
        $result[$car['name']] = $car['count'];
    }
}
Как вариант$arr = [['name' => 'ford', 'count' => 2],
    ['name' => 'ford', 'count' => 8],
    ['name' => 'lada', 'count' => 9],
    ['name' => 'lada', 'count' => 2]];

$result = [];
foreach($arr as $car) {
    if (!isset($result[$car['name']]) || $result[$car['name']] < $car['count']) {
        $result[$car['name']] = $car['count'];
    }
}