通过多个键对多维数组进行排序

Question

我试图通过多个键对多维数组进行排序,我不知道从哪里开始.我看着uasort,但不太确定如何为我需要的东西编写函数.

我需要按州,然后是event_type,然后按日期排序.

我的数组看起来像这样:

    Array
(
    [0] => Array
        (
            [ID] => 1
            [title] => Boring Meeting
            [date_start] => 2010-07-30
            [time_start] => 06:45:PM
            [time_end] => 
            [state] => new-york
            [event_type] => meeting
        )

    [1] => Array
        (
            [ID] => 2
            [title] => Find My Stapler
            [date_start] => 2010-07-22
            [time_start] => 10:45:AM
            [time_end] => 
            [state] => new-york
            [event_type] => meeting
        )

    [2] => Array
        (
            [ID] => 3
            [title] => Mario Party
            [date_start] => 2010-07-22
            [time_start] => 02:30:PM
            [time_end] => 07:15:PM
            [state] => new-york
            [event_type] => party
        )

    [3] => Array
        (
            [ID] => 4
            [title] => Duct Tape Party
            [date_start] => 2010-07-28
            [time_start] => 01:00:PM
            [time_end] => 
            [state] => california
            [event_type] => party
        )
...... etc

Answer 1

你需要 array_multisort

$mylist = array(
    array('ID' => 1, 'title' => 'Boring Meeting', 'event_type' => 'meeting'),
    array('ID' => 2, 'title' => 'Find My Stapler', 'event_type' => 'meeting'),
    array('ID' => 3, 'title' => 'Mario Party', 'event_type' => 'party'),
    array('ID' => 4, 'title' => 'Duct Tape Party', 'event_type' => 'party')
);

# get a list of sort columns and their data to pass to array_multisort
$sort = array();
foreach($mylist as $k=>$v) {
    $sort['title'][$k] = $v['title'];
    $sort['event_type'][$k] = $v['event_type'];
}
# sort by event_type desc and then title asc
array_multisort($sort['event_type'], SORT_DESC, $sort['title'], SORT_ASC,$mylist);

从PHP 5.5.0开始:

array_multisort(array_column($mylist, 'event_type'), SORT_DESC,
                array_column($mylist, 'title'),      SORT_ASC,
                $mylist);

$mylist 就是现在:

array (
  0 => 
  array (
    'ID' => 4,
    'title' => 'Duct Tape Party',
    'event_type' => 'party',
  ),
  1 => 
  array (
    'ID' => 3,
    'title' => 'Mario Party',
    'event_type' => 'party',
  ),
  2 => 
  array (
    'ID' => 1,
    'title' => 'Boring Meeting',
    'event_type' => 'meeting',
  ),
  3 => 
  array (
    'ID' => 2,
    'title' => 'Find My Stapler',
    'event_type' => 'meeting',
  ),
)

Answer 2

你可以做到usort.该$cmp_function参数可以是:

function my_sorter($a, $b) {
    $c = strcmp($a['state'], $b['state']);
    if($c != 0) {
        return $c;
    }

    $c = strcmp($a['event_type'], $b['event_type']);
    if($c != 0) {
        return $c;
    }

    return strcmp($a['date_start'], $b['date_start']);
}

对于PHP 5.3中的任意数量的字段,您可以使用闭包来创建比较函数:

function make_cmp($fields, $fieldcmp='strcmp') {
    return function ($a, $b) use (&$fields) {
        foreach ($fields as $field) {
            $diff = $fieldcmp($a[$field], $b[$field]);
            if($diff != 0) {
                return $diff;
            }
        }
        return 0;
    }
}

usort($arr, make_cmp(array('state', 'event_type', 'date_start')))

对于PHP 5.3中任意数量的不同类型的字段:

function make_cmp($fields, $dfltcmp='strcmp') {
    # assign array in case $fields has no elements
    $fieldcmps = array();
    # assign a comparison function to fields that aren't given one
    foreach ($fields as $field => $cmp) {
        if (is_int($field) && ! is_callable($cmp)) {
            $field = $cmp;
            $cmp = $dfltcmp;
        }
        $fieldcmps[$field] = $cmp;
    }
    return function ($a, $b) use (&$fieldcmps) {
        foreach ($fieldcmps as $field => $cmp) {
            $diff = call_user_func($cmp, $a[$field], $b[$field]);
            if($diff != 0) {
                return $diff;
            }
        }
        return 0;
    }
}

function numcmp($a, $b) {
    return $a - $b;
}
function datecmp($a, $b) {
    return strtotime($a) - strtotime($b);
}
/**
 * Higher priority come first; a priority of 2 comes before 1.
 */
function make_evt_prio_cmp($priorities, $default_priority) {
    return function($a, $b) use (&$priorities) {
        if (isset($priorities[$a])) {
            $prio_a = $priorities[$a];
        } else {
            $prio_a = $default_priority;
        }
        if (isset($priorities[$b])) {
            $prio_b = $priorities[$b];
        } else {
            $prio_b = $default_priority;
        }
        return $prio_b - $prio_a;
    };
}

$event_priority_cmp = make_evt_prio_cmp(
    array('meeting' => 5, 'party' => 10, 'concert' => 7), 
    0);

usort($arr, make_cmp(array('state', 'event' => $event_priority_cmp, 'date_start' => 'datecmp', 'id' => 'numcmp')))

Answer 3

PHP7使飞船运算符（<=>）又称为“组合比较运算符”或“三向比较运算符”使多列排序超级容易。

资源：https : //wiki.php.net/rfc/combined-comparison-operator

通过多列排序就像在运算符的两边编写平衡/关系数组一样简单。容易做！

我没有用过，uasort()因为我看不到需要保留原始索引。

代码：（演示）

$array = [
    ['ID' => 1, 'title' => 'Boring Meeting', 'date_start' => '2010-07-30', 'event_type' => 'meeting', 'state' => 'new-york'],
    ['ID' => 2, 'title' => 'Find My Stapler', 'date_start' => '2010-07-22', 'event_type' => 'meeting', 'state' => 'new-york'],
    ['ID' => 3, 'title' => 'Mario Party', 'date_start' => '2010-07-22', 'event_type' => 'party', 'state' => 'new-york'],
    ['ID' => 4, 'title' => 'Duct Tape Party', 'date_start' => '2010-07-28', 'event_type' => 'party', 'state' => 'california']
];

usort($array, function($a, $b) {
    return [$a['state'], $a['event_type'], $a['date_start']] <=> [$b['state'], $b['event_type'], $b['date_start']];
});

var_export($array);

输出量

array (
  0 => 
  array (
    'ID' => 4,
    'title' => 'Duct Tape Party',
    'date_start' => '2010-07-28',
    'event_type' => 'party',
    'state' => 'california',
  ),
  1 => 
  array (
    'ID' => 2,
    'title' => 'Find My Stapler',
    'date_start' => '2010-07-22',
    'event_type' => 'meeting',
    'state' => 'new-york',
  ),
  2 => 
  array (
    'ID' => 1,
    'title' => 'Boring Meeting',
    'date_start' => '2010-07-30',
    'event_type' => 'meeting',
    'state' => 'new-york',
  ),
  3 => 
  array (
    'ID' => 3,
    'title' => 'Mario Party',
    'date_start' => '2010-07-22',
    'event_type' => 'party',
    'state' => 'new-york',
  ),
)

PS7和更高版本的ps Arrow语法（演示）...

usort($array, fn($a, $b) => [$a['state'], $a['event_type'], $a['date_start']] <=> [$b['state'], $b['event_type'], $b['date_start']]);