如何在php中通过比较值来查找二维数组的键

function searchKeyInArray($value, $array) {
    foreach ($array as $key => $subArray) {
        if (in_array($value, $subArray)) {
            return $key;
        }
    }
    return null;
}

$students = array(
    array('name' => 'Alice', 'age' => 20),
    array('name' => 'Bob', 'age' => 22),
    array('name' => 'Charlie', 'age' => 21)
);

$key = searchKeyInArray('Bob', $students);
if ($key !== null) {
    echo "Bob's key is: " . $key;
} else {
    echo "Bob not found in the array.";
}

Bob's key is: 1