如何按日期对平面数组的DateTime值进行分组？

Question

我有一个列出日期时间的数组。如何将具有相同日期的数组分组。

$array = [
   "2019-07-17 10:02:00",
   "2019-07-17 12:00:00",
   "2019-07-18 08:00:00",
   "2019-07-19 01:00:00",
   "2019-07-19 02:00:00"
];

指望

result

：

$result = [
       0 => [
            "2019-07-17 10:02:00",
            "2019-07-17 12:00:00"
       ],
      1 => [
            "2019-07-18 08:00:00"
       ],
       2 => [
            "2019-07-19 01:00:00",
            "2019-07-19 02:00:00"
       ]
];

trone this：

Answer 1

$grouped = [];
foreach ($array as $dateString) {
    $dateObject = new \DateTime($dateString);
    $grouped[$dateObject->format('Y-m-d')][] = $dateString;
}
$grouped = array_values($grouped);
var_dump($grouped);

example

.