Question

我正在学习PHP中的数组。我正在研究我面临问题的多维数组。我想在场地和日期打印输出基础。

以下是多维数组示例的说明：

 Array
(
    [0] => Array
        (
            [venue] => chicago
            [course] => science
            [time] => 2pm
            [date]=>jan2016-feb-2017

        )

    [1] => Array
        (
             [venue] => newyork
            [course] => robotics
            [time] =>3pm
            [date]=>jan2016-feb-2017
        )

    [2] => Array
        (
            [venue] => newyork
            [course] => science
            [time] => 4pm
              [date]=>mar2017-feb-2018
        )
     [3] => Array
        (
            [venue] => chicago
            [course] => robtics
            [time] => 4pm
            [date]=>mar2017-feb-2018
        )
 [4] => Array
        (
            [venue] => chicago
            [course] => robotics
            [time] => 2pm
            [date]=>jan2016-feb-2017

        )
  [5] => Array
        (
            [venue] => chicago
            [course] => science
            [time] => 4pm
            [date]=>mar2017-feb-2018

        )
 [6] => Array
        (
             [venue] => newyork
            [course] => robotics
            [time] =>1pm
            [date]=>mar2017-feb-2018
        )

    [7] => Array
        (
            [venue] => newyork
            [course] => science
            [time] => 5pm
              [date]=>mar2017-feb-2018
        )

)

这是我想要的所需输出：

chicago
Date:jan2016-feb-2017
science  2pm
robotics  2pm 

chicago
Date:mar2017-feb-2018
science  4pm
robotics  4pm 


newyork 
Date:jan2016-feb-2017
science 4pm
robotics 3pm 

newyork 
Date:mar2017-feb-2018
science 5pm
robotics 1pm

我想打印场地和日期的输出基础。请帮助我们

我目前的代码：

usort($events, function($a, $b) {
    return strcmp($a['venue'], $b['venue']);
});
$previousVenue = null;
foreach ($events as $event) {

    // check if this venue is the same as the previous, output header if not
    if ($event['venue'] != $previousVenue) {
        echo "<h3>$event[venue]</h3>";
        echo "$event[date]";
    }
    // always output course and time
    echo "$event[course] $event[time]<br>";

    // current venue becomes previous venue
    $previousVenue = $event['venue'];
}

我设法用场地搜索它，但我无法按照日期打印它。

Answer 1

您可以使用usort或uasort根据一个或多个键对多维数组进行排序。例如。你可以分别根据场地和日期对它进行排序，然后迭代结果并打印出来。

uasort($events, function($a, $b) {
    $venueComparison = strcmp($a['venue'], $b['venue']);
    if (!$venueComparison) {
        return compare_date($a['date'], $b['date']);
    }
});

foreach ($events as $event) {
    echo '...';
}

或者你可以迭代多维数组并将其转换为更合适的结构。

$groupedEvents = array();
foreach ($events as $event) {
    if (!array_key_exists($event['venue'], $groupedEvents)) {
        $groupedEvents[$event['venue']] = array();
    }
    $groupedEvents[$event['venue']][] = $event;
}

foreach ($groupedEvents as $venue => $events) {
    usort($events, 'compare_date');
    foreach ($events as $event) {
        echo '...';
    }
}

无论哪种方式，您都需要一些能够解析日期范围并对其进行排序的东西。您将需要自己进行解析，然后决定是否要按开始日期或结束日期排序。

或者，如果可能，您可以切换到更容易排序的日期范围格式。例如。 ISO 8601.

一次是在日期的第一部分拆分strotime()，然后只比较生成的时间戳。像这样：

function compare_date($a, $b) {
    return strtotime(substr($a, 0, strpos($a, '-'))) - strtotime(substr($b, 0, strpos($b, '-')));
}

Answer 2

您需要将日期设为我们可以“订购”的内容。如果你这样做，你可以再次运行usort。（php7方式顺便说一下）。希望这有用...编辑，有点凌乱的代码，但也许你得到它:)干杯

   /*-----( example array )------*/
        $arr =  array(
           array(
               'venue' => 'chicago',
               'course' => 'science',
               'time' => '2pm',
               'date' => 'jan2016-feb-2017',
           ),
           array(
               'venue' => 'amsterdam',
               'course' => 'science',
               'time' => '4pm',
               'date' => 'jan2016-feb-2017',
           ),
           array(
               'venue' => 'chicago',
               'course' => 'science',
               'time' => '2pm',
               'date' => 'jan2016-feb-2017',
           ),
        );

        /*-----( remove dublicates )-----*/
        $s = array_map('serialize', $arr);
        $u = array_unique($s);
        $arr = array_intersect_key($arr, $u);

        /*-----( sort based on venue)------*/
        usort($arr, function($a, $b) {
            return $a['venue'] <=> $b['venue'];
        });

        /*----( edit, order on dates )----*/
        foreach($arr as $k => $a)
        {
            $t = explode('-',$a['date']);
            $arr[$k]['t_date'] = isset($t[0]) ? $t[0] :null;
        }

        usort($arr, function($a, $b) {
            return $a['t_date'] <=> $b['t_date'];
        });

        /*----( output )----*/
        foreach($arr as $a)
        {
            foreach($a as $k => $v)
            {
                echo $k == 'venue' ? $v : $k.' '.$v;
                echo '<br>';
            }
            echo '<br>';
        }

尝试沿多维数组搜索并打印出所需的输出

2 个答案: