Question

我在PHP数组中有一个日期/时间项的列表，其格式如下：

2019-03-19 00:00:00
2019-03-19 02:30:00
2019-03-19 05:00:00
2019-03-19 14:30:00
2019-03-19 23:59:59

etc.

我确信这很容易，我只是无法将头缠住它。我使用什么方程式来显示最接近当前时间的项目，而又不会越过。

因此，如果当前时间是22:00:00，我想显示项目14:30:00，而不是23:59:59。

Answer 1

由于您的时间在Y-m-d H:i:s中，因此您可以将它们作为字符串进行比较，并使用简单的foreach循环获取结果：

$dates = array('2019-03-19 00:00:00',
               '2019-03-19 02:30:00',
               '2019-03-19 05:00:00',
               '2019-03-19 14:30:00',
               '2019-03-19 23:59:59');
$now = date('Y-m-d H:i:s');
$latest = '';
// add sort($dates) here if they are not already sorted.
foreach ($dates as $date) {
    if ($date > $now) break;
    $latest = $date;
}
echo $latest;

Demo on 3v4l.org

请注意，此代码假定您的日期已经过排序，否则请在sort($dates)循环之前添加foreach。

Answer 2

首先将所有日期转换为此格式

$changed_date_1 = date('YmdHis', strtotime($orignaldate_1));
$changed_date_2 = date('YmdHis', strtotime($orignaldate_2));
$changed_date_3 = date('YmdHis', strtotime($orignaldate)_3);

因此2019-03-19 00:00:00将变为20190319000000，依此类推，现在可以轻松进行比较了。而不是运行一个遍历所有这些日期的foreach循环

$closestdate= date('Y-m-d H:i:s');//intaily set it to current date
$closest_difference= 99999999999999999;//intaily set a big value, more than 15 digits
foreach($datesArray as $item){
   $difference = $item - date('YmdHis');
   if($difference < $closest_difference){
      $closes_difference = $difference;
      $closestdate = $item;//this item is closest one. in next iteration this may change
   }
}
echo $Closesdate;

Answer 3

/**
 * Gets the nearest moment of the same day as $today.
 *
 * @param string[] $dates - A list of dates (needed format: "Y-m-d H:i:s")
 * @param string|null $today - The date used for comparaison. (default is current date)
 * @return string|bool - Returns the nearest date, or false.
 */
function getNearestDate(array $dates, ?string $today = null) {
    if (!$today) {
        $today = date('Y-m-d H:i:s');
    }

    $fnDT = function($d) {
        return DateTime::createFromFormat('Y-m-d H:i:s', $d);
    };

    usort($dates, function($a, $b) use ($fnDT, $today) {
        $da = abs($fnDT($today)->getTimestamp() - $fnDT($a)->getTimestamp());
        $db = abs($fnDT($today)->getTimestamp() - $fnDT($b)->getTimestamp());

        return $da - $db;
    });

    $nearest = $dates[0];

    if ($fnDT($nearest)->format('Y-m-d') !== $fnDT($today)->format('Y-m-d')) {
        print_r('No date of the same day.');
        return false;
    }

    return $nearest;
}

Test it on 3v4l.org

显示最接近当前时间的项目

3 个答案: