獲取PHP

Question

我有以下陣列從多維數組前5名的值：

Array ( 
[0] => Array ( 
    [count] => 9 
    [user_id] => 2 
) 
[1] => Array ( 
    [count] => 25 
    [user_id] => 1 
) 
[2] => Array ( 
    [count] => 20 
    [user_id] => 3) 
[3] => Array ( 
    [count] => 6 
    [user_id] => 56) 
[4] => Array ( 
    [count] => 2 
    [user_id] => 37) 
[5] => Array ( 
    [count] => 1 
    [user_id] => 0 
)) 

這僅僅是一個樣品。實際的數組將包含更多的子數組。

我需要能夠從「count」中獲得前五個值並將它們與相關的「user_id」一起存儲。

最後的結果需要是這個樣子：

Array ( 
[0] => Array ( 
    [count] => 25 
    [user_id] => 1 
) 
[1] => Array ( 
    [count] => 20 
    [user_id] => 3 
) 
[2] => Array ( 
    [count] => 9 
    [user_id] => 2 
) 
[3] => Array ( 
    [count] => 6 
    [user_id] => 56 
) 
[4] => Array ( 
    [count] => 2 
    [user_id] => 37 
) 
[5] => Array ( 
    [count] => 1 
    [user_id] => 0 
)) 

如果可以做到這一點，只需重新排序的陣列，這是罰款。

謝謝！

Answer 1

您正在尋找usort和array_slice。

例子：

<?php 

$array = array(
    array(
    'count' => 9, 
    'user_id' => 2 
), 
    array(
    'count' => 25, 
    'user_id' => 1 
), 
    array(
    'count' => 20, 
    'user_id' => 3 
), 
    array(
    'count' => 6, 
    'user_id' => 56 
), 
    array(
    'count' => 2, 
    'user_id' => 37 
), 
    array(
    'count' => 1, 
    'user_id' => 0 
) 
); 

function usort_callback($a, $b) 
{ 
    if ($a['count'] == $b['count']) 
    return 0; 

    return ($a['count'] > $b['count']) ? -1 : 1; 
} 

usort($array, 'usort_callback'); 

$top5 = array_slice($array, 0, 5); 

print_r($top5); 

輸出：

Array 
(
    [0] => Array 
     (
      [count] => 25 
      [user_id] => 1 
     ) 

    [1] => Array 
     (
      [count] => 20 
      [user_id] => 3 
     ) 

    [2] => Array 
     (
      [count] => 9 
      [user_id] => 2 
     ) 

    [3] => Array 
     (
      [count] => 6 
      [user_id] => 56 
     ) 

    [4] => Array 
     (
      [count] => 2 
      [user_id] => 37 
     ) 

) 

Answer 2

usort($array, function ($a, $b) { return $b['count'] - $a['count']; }); 
$top5 = array_slice($array, 0, 5);