php对数组重新排序

Question

我有一个按年份和月份分隔的条目数组，如下所示。我需要对此数组进行排序，以便条目先按年份“分组”，然后按类别“分组”。

Array
(
    [Oct 2011] => Array
        (
            [0] => Array
                (
                    [title] => CAD Drawing Updates
                    [file] => /gm-June2010-driver.pdf
                    [category] => Windows
                )
        )


    [Sep 2011] => Array
        (
            [0] => Array
                (
                    [title] => title
                    [file] => /gm-June2010-driver.pdf
                    [category] => Windows
                )

            [1] => Array
                (
                    [title] => edges
                    [file] => /gm-June2010-driver.pdf
                    [category] =>Walling
                )

            [2] => Array
                (
                    [title] => Specification update
                    [file] => /gm-June2010-driver.pdf
                    [category] => Windows
                )
        )
)

所以这就是我要找的东西。

Array
(
    [Oct 2011] => Array
        (
                [Windows] => Array
                        (
                            [0] => Array
                                (
                                    [title] => CAD Drawing Updates
                                    [file] => /gm-June2010-driver.pdf
                                )                       
                        )
        )


    [Sep 2011] => Array
        (
                [Windows] => Array
                                (
                            [0] => Array
                                (
                                    [title] => title
                                    [file] => /gm-June2010-driver.pdf
                                    [category] => Windows
                                )


                            [1] => Array
                                (
                                    [title] => Specification update
                                    [file] => /gm-June2010-driver.pdf
                                    [category] => Windows
                                )                                                               
                                )   
                [Walling] => Array
                                (
                            [0] => Array
                                (
                                    [title] => edges
                                    [file] => /gm-June2010-driver.pdf
                                    [category] => Curtain Walling
                                )                                                               
                                )                                            
        )
)

我不确定这是否是一个排序功能的工作，任何帮助都将不胜感激，谢谢。

Answer 1

不，这不能用排序函数来完成，你需要通过使用嵌套的foreach循环遍历原始数组来创建一个新的数组。

$newArr = array();
foreach($arr as $month => items) {
  foreach($items as $data) {
    $newArr[$month][$data["category"]][] = $data;
  }
}

Answer 2

你不想排序，只想重命名关键字。PHP数组不支持直接重命名键，因此您需要首先创建一个新数组，该数组是在保留现有值的同时使用新键构建的。

最后，您可以用新数组替换原来的数组：

$rekeyed = array();
foreach($array as $monthYear => &$value)
{
    $r = sscanf($monthYear, '%s %d', $month, $year);
    if ($r != 2) throw new Exception(sprintf('Invalid Key "%s".', $monthYear));
    $categories = array();
    foreach($value as &$item)
    {
        $category =& $item['category'];
        unset($item['category']);
        $categories[$category][] =& $item;
    }
    unset($item);
    $value =& $categories;
    unset($categories);    
    $rekeyed[$year][$month] =& $value;
}
unset($value);
$array =& $rekeyed;
unset($rekeyed);
print_r($array);

输出：

Array
(
    [2011] => Array
        (
            [Oct] => Array
                (
                    [Windows] => Array
                        (
                            [0] => Array
                                (
                                    [title] => CAD Drawing Updates
                                    [file] => /gm-June2010-driver.pdf
                                )

                        )

                )

            [Sep] => Array
                (
                    [Windows] => Array
                        (
                            [0] => Array
                                (
                                    [title] => title
                                    [file] => /gm-June2010-driver.pdf
                                )

                        )

                    [Walling] => Array
                        (
                            [0] => Array
                                (
                                    [title] => edges
                                    [file] => /gm-June2010-driver.pdf
                                )

                        )

                )

        )

)

Demo

Answer 3

我认为你应该关注的函数是uasort。

http://www.php.net/manual/en/function.uasort.php

首先在主数组上进行排序，对于数组中的每个元素，在子数组上进行usort。