PHP数组操作

Question

我有下面的数组

Array
(
    [0] => Array
        (
            [reservation_time] => 08:30
            [user_name] => 
            [reason] => 
            [comments] => recursive
            [reservation_date] => 2011-07-14
        )
    [1] => Array
        (
            [reservation_time] => 09:00
            [user_name] => 
            [reason] => 
            [comments] => recursive
            [reservation_date] => 2011-07-14
        )
    [2] => Array
        (
            [reservation_time] => 09:30
            [user_name] => 
            [reason] => 
            [comments] => recursive
            [reservation_date] => 2011-07-14
        )
    [3] => Array
        (
            [reservation_time] => 08:30
            [user_name] => 
            [reason] => 
            [comments] => recursive
            [reservation_date] => 2011-07-15
        )
    [4] => Array
        (
            [reservation_time] => 09:00
            [user_name] => 
            [reason] => 
            [comments] => recursive
            [reservation_date] => 2011-07-15
        )
    [5] => Array
        (
            [reservation_time] => 09:30
            [user_name] => 
            [reason] => 
            [comments] => recursive
            [reservation_date] => 2011-07-15
        )
    [6] => Array
        (
            [reservation_time] => 08:30
            [user_name] => 
            [reason] => 
            [comments] => recursive
            [reservation_date] => 2011-07-16
        )
)

数组应该是

Array(
 [2011-07-14] => Array
    (
            [0] => Array
                (
                    [reservation_time] => 08:30
                    [user_name] => 
                    [reason] => 
                    [comments] => recursive
                    [reservation_date] => 2011-07-14
                )
            [1] => Array
                (
                    [reservation_time] => 09:00
                    [user_name] => 
                    [reason] => 
                    [comments] => recursive
                    [reservation_date] => 2011-07-14
                )
    )
 [2011-07-15]  => Array
 ( 
    [0] => Array
        (
            [reservation_time] => 08:30
            [user_name] => 
            [reason] => 
            [comments] => recursive
            [reservation_date] => 2011-07-15
        )
)

如何循环此数组以获得所需的输出

的问候Nisanth

Answer 1

$new_array = array();
foreach($array as $item) {
  $new_array[$item['reservation_date']][] = $item;
}

Answer 2

有时按子键(任何子键)分组多维数组是很好的。这基本上是可接受的答案，但重载了实际的数组:

print_r($array('reservation_date')); # group by subkey 'reservation_date'

代码(演示):

$array = array(
  0 => array(
    'reservation_time' => '08:30',
    'user_name' => '',
    'reason' => '',
    'comments' => 'recursive',
    'reservation_date' => '2011-07-14',
  ),
  1 => array(
    'reservation_time' => '09:00',
    'user_name' => '',
    'reason' => '',
    'comments' => 'recursive',
    'reservation_date' => '2011-07-14',
  ),
  2 => array(
    'reservation_time' => '09:30',
    'user_name' => '',
    'reason' => '',
    'comments' => 'recursive',
    'reservation_date' => '2011-07-14',
  ),
  3 => array(
    'reservation_time' => '08:30',
    'user_name' => '',
    'reason' => '',
    'comments' => 'recursive',
    'reservation_date' => '2011-07-15',
  ),
  4 => array(
    'reservation_time' => '09:00',
    'user_name' => '',
    'reason' => '',
    'comments' => 'recursive',
    'reservation_date' => '2011-07-15',
  ),
  5 => array(
    'reservation_time' => '09:30',
    'user_name' => '',
    'reason' => '',
    'comments' => 'recursive',
    'reservation_date' => '2011-07-15',
  ),
  6 => array(
    'reservation_time' => '08:30',
    'user_name' => '',
    'reason' => '',
    'comments' => 'recursive',
    'reservation_date' => '2011-07-16',
  ),
);
// overload $array with a function
$array = function($key) use ($array) {
    $r = array();
    foreach($array as $v) 
        $r[$v[$key]][] = $v;
    return $r;
};
// request subkey per parameter:
print_r($array('reservation_date'));
print_r($array('reservation_time'));

Answer 3

从我自己的PHP代码，我有这个函数。就叫make_assoc_from_list($your_array, 'reservation_date'):

// makes associative array from normal list
//      - $list - list
//      - $key - key of each item which will be the associative key
//
function make_assoc_from_list($list, $key)
{
        $assoc = array();
        if ($list === null)
                $list = array();
        foreach ($list as $item)
                $assoc[$item[$key]] = $item;
        return $assoc;
}

Answer 4

$new = array();
foreach ($array as $entry) {
    if (!array_key_exists($entry['reservation_date'], $new)) $new[$entry['reservation_date']] = array();
    $new[$entry['reservation_date']][] = $entry;
}