PHP返回数字在一系列数组之间的键

Question

If I have one php array $date like below:

Array
(
    [100] => Array
    (
        [card] => 5244
        [start_date] => 2019-05-03 00:00:00
    )
    [93] => Array
    (
        [card] => 9526
        [start_date] => 2019-05-20 00:00:00
    )
    [65] => Array
    (
        [card] => 1537
        [start_date] => 2019-07-09 00:00:00
    )

    ...
)

and I also have some random numbers like: 1, 34, 67, 120...

My question is that :

• when the random number is 1 or 34, then compare it with $date's keys (100, 93, 65), then return empty,
• when the random number is 67, it will return $date[65], because this number is between 65 and 93.
• when the random number is 120, it will return $date[100], because this number is between 100 and ∞ (infinite).

If the array $date only has a few elements, I can use for or foreach to compare the keys, but if the array $date has lots of elements, do we have an easy way to do that please?

Answer 1

$dates = [
    100 => [
        'card' => 5244,
        'start_date' => '2019-05-03 00:00:00'
    ],
    93 => [
        'card' => 9526,
        'start_date' => '2019-05-20 00:00:00'
    ],
    65 => [
        'card' => 1537,
        'start_date' => '2019-07-09 00:00:00'
    ]
];
$randoms = [1, 34, 67, 120];
foreach ($randoms as $random) {
    $matchDate = $this->matchDates($dates, $random);
    var_dump($matchDate);
}

/**
 * @param array $dates
 * @param $random
 * @return array
 */
protected function matchDates(array $dates, $random): array
{
    $minKey = min(array_keys($dates));
    $maxKey = max(array_keys($dates));

    if ($random < $minKey) {
        return [];
    }

    if ($random > $maxKey) {
        return $dates[$maxKey];
    }

    foreach ($dates as $key => $date) {
        if ($random >= $key) {
            return $date;
        }
    }
}

Returns as expected :

[]
[]
array:2
  "card" => 1537
  "start_date" => "2019-07-09 00:00:00"
]
array:2
  "card" => 5244
  "start_date" => "2019-05-03 00:00:00"
]