如何計算PHP數組中的唯一值

Question

我正在從數據庫中獲取以下格式的數據，我只想獲取數據，在哪個國家/地區有多少家餐廳名稱（數量），我該怎么做？ 我如何更改以下數組/對象在php中？

stdClass Object
(
    [_id] => 5ce405ced246f713b6256f3a
    [location] => stdClass Object
        (
            [country] => Kuwait
        )
    [employerDetails] => Array
        (
            [0] => stdClass Object
                (
                    [restraunt_name] => test1
                 )
        )

    [_id] => 5ce405ced246f713b6277373
    [location] => stdClass Object
        (
            [country] => Kuwait
        )
    [employerDetails] => Array
        (
            [0] => stdClass Object
                (
                    [restraunt_name] => test2
                 )
        )       
    ....
 )

Answer 1

由於對象可以具有相同的鍵，因此我假設您為每個餐廳對象都有一個對象數組。

首先，我建議僅獲取將數組分開的國家/地區：

foreach($objectArray as $restaurant)
    $countries[] = $restaurant->location->country;

現在，您可以使用array-count-values根據國家/地區獲取對象數：

print_r(array_count_values($countries));

Answer 2

$countries = array();
//first get all countries list
foreach ($array as $data) {
    if (!in_array($data->location->country, $countries)) {
        array_push($countries, $data->location->country);
    }
}
//get restraunt county wise
foreach ($array as $key => $data) {
    //if (in_array($data->location->country, $countries)) {
    if (!empty($data->location->country) && !empty($data->employerDetails[0]->restraunt_name)) {
        $countries_f[$data->location->country][$key] = $data->employerDetails[0]->restraunt_name;
    }
    //}
}
//get count of restraunt in each ocuntry
foreach ($countries as $cnt) {
    echo 'count of' . $cnt = count($countries_f[$cnt]) . '<br />';
}

echo "<pre>";
print_r($countries_f);

die;