僅通過特定的鍵值對「內部」數組排序 - 使用uasort（）？

Question

Array opareas 
(
[0] => Array 
(
[name] = => array('opname1') 

[subcats] => Array 
    (
     [0] => Array 
      (
       [amount] => 9883 
       [perc] => 112.61394712853236 
      ) 

     [1] => Array 
      (
       [amount] => 1 
       [perc] => 0.011394712853236098 
      ) 

     [2] => Array 
      (
       [amount] => 3679 
       [perc] => 41.921148587055605 
      ) 

    ) 

) 

[1] => Array 
(
[name] = => array('opname2') 

[subcats] => Array 
    (
     [0] => Array 
      (
       [amount] => 12166 
       [perc] => 56.8584380987989 
      ) 

     [1] => Array 
      (
       [amount] => 1473 
       [perc] => 6.884142636818245 
      ) 

     [2] => Array 
      (
       [amount] => 955 
       [perc] => 4.463242510632331 
      ) 

     [3] => Array 
      (
       [amount] => 6802 
       [perc] => 31.789503201383372 
      ) 

    ) 

) 

PHP非常適合排序數組，但我無法弄清楚在遇到這個問題時要使用什麼。請看一下上面的數組。

我想排序innner subcats[] array by perc -key從低到高。

我想要得到的結果是：

Array opareas 
(
[0] => Array 
(
[name] = => array('opname1') 

[subcats] => Array 
    (
     [0] => Array 
      (
       [amount] => 1 
       [perc] => 0.011394712853236098 //Lowest percentage value 
      ) 

     [1] => Array 
      (
       [amount] => 3679 
       [perc] => 41.921148587055605 
      ) 

     [2] => Array 
      (
       [amount] => 9883 
       [perc] => 112.61394712853236 //Highest percentage value 
      ) 

    ) 

) 

[1] => Array 
(
[name] = => array('opname2'); 

[subcats] => Array 
    (
     [0] => Array 
      (
       [amount] => 955 
       [perc] => 4.463242510632331 //Lowest percentage value 
      ) 

     [1] => Array 
      (
       [amount] => 1473 
       [perc] => 6.884142636818245 
      ) 

     [2] => Array 
      (
       [amount] => 12166 
       [perc] => 56.8584380987989 
      ) 

     [3] => Array 
      (
       [amount] => 6802 
       [perc] => 31.789503201383372 //Highest percentage value 
      ) 

    ) 

) 

我試過這個：

class whateverArray { 

    private function sort_subcats_perc($a, $b) {    
     if ($a['subcats']['perc'] == $b['subcats']['perc']) {return 0;} 
     return ($a['subcats']['perc'] < $b['subcats']['perc']) ? -1 : 1; 
    } 

    public function showStuff() { 
     $opareas = array(); //Given above 

     //Sort subcat array from low to high based on perc-key 
     uasort($opareas, array($this, 'sort_subcats_perc')); 
    } 

); 

} 

我不想實際opareas[0]和operas[1]切換位置（是使用我試過的函數時發生的事情），我只想要內部數組subcats []來改變它的基於perc-field/key的順序。這可能與uasort？或者其他PHP內置的優秀分類功能？

Answer 1

如果你想對子數組進行排序，你的比較函數需要有點不同。然後，您可以通過引用循環訪問外部數組，以便subcats將被排序。

foreach ($opareas as &$value) { 
    usort($value['subcats'], function($a, $b) { 
     if ($a['perc'] > $b['perc']) return 1; 
     if ($a['perc'] < $b['perc']) return -1; 
     return 0; 
    }); 
} 
unset($value); // unset the reference after looping 

您可以使用usort。如果您關心subcats中的密鑰順序，則只需使用uasort即可。

Answer 2

$opareas = array(); //Given above 
foreach($opareas as &$oparea){ 
//Sort subcat array from low to high based on perc-key 
uasort($oparea, array($this, 'sort_subcats_perc')); 
} 

可以在這裏解決。