尝试沿着多维数组搜索并打印出所需的输出

Question

我正在学习PHP中的数组。我正在研究多维数组，在其中我面临一个问题。我想打印的输出基础上的地点和日期也。

下面是示例多维数组的说明：

 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
        )

)

下面是我想要的输出：

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 

我想打印的输出基础上的地点和日期also.please帮助我的伙计们

我现在的代码是：

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'];
}

我设法搜索它的地点，但我无法打印它的日期。

Answer 1

您可以使用乌斯托或乌萨特根据一个或多个键对多维数组进行排序。例如，您可以根据地点和日期对其进行排序，然后对结果进行迭代并打印出来。

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，您可以迭代多维数组，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，您都需要一些分析日期范围并对其进行排序的内容。您需要自己进行解析，然后决定是按照开始日期还是结束日期进行排序。

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

一种方法是在约会的第一部分分割频闪时间()，然后比较产生的时间戳。就像这样：

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

Answer 2

你需要安排一些我们可以“点菜”的日期。如果你这样做，你可以再运行一次。( php7的方式)希望这是helpfull...edit，有点乱七八糟的代码，但也许你会明白:)

   /*-----( 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>';
        }