PHP通過數值計數排序子數組，然後通過子數組鍵

Question

排序多維數組最簡單的方法是什麼？我需要排序，使輸出顯示與子陣列值的最高計數那麼由子陣列的鍵按字母順序排序：

因此，像這樣：

MyArray(
    subarray4('val1') 
    subarray2('val1') 
    subarray3('val1', 'val2', 'val3') 
    subarray1('val1', 'val2', 'val3') 
) 

會看更是這樣的：

MyArray(
    subarray1('val1', 'val2', 'val3') 
    subarray3('val1', 'val2', 'val3') 
    subarray2('val1') 
    subarray4('val1') 
) 

Answer 1

兩個步驟這裏，根據子陣列數，然後通過循環陣列排序每個子陣列「字母數字」第一排序陣列。

$myArray = array(
    array('val1', 'val2'), 
    array('val3'), 
    array('val7', 'val6', 'val5', 'val4'), 
    array('val8', 'val9', 'val10'), 
); 

// sort primary array by subarray count 
uasort($myArray, function ($a, $b) { 
    $a = count($a); 
    $b = count($b); 
    return ($a == $b) ? 0 : (($a > $b) ? -1 : 1); 
}); 

// now sort each subarray alphanumerically 
foreach ($myArray as $key => $arr) { 
    natsort($myArray[$key]); // letters - alpha, numbers - numeric 
    // note: ignoring $arr because sorting it does not affect $myArray 
} 

print '<pre>'; 
print_r($myArray); 
print '</pre>'; 

輸出：

Array 
(
    [2] => Array 
     (
      [3] => val4 
      [2] => val5 
      [1] => val6 
      [0] => val7 
     ) 

    [3] => Array 
     (
      [0] => val8 
      [1] => val9 
      [2] => val10 
     ) 

    [0] => Array 
     (
      [0] => val1 
      [1] => val2 
     ) 

    [1] => Array 
     (
      [0] => val3 
     ) 

) 

的uasort排序算法被切斷，從這裏粘貼：Sorting array by count of subarray

Answer 2

$array = array(
    array('val1'), 
    array('val1'), 
    array('val1', 'val2', 'val3'), 
    array('val1', 'val2', 'val3'), 
); 

function sortByCount($a, $b) { 
    $a = count($a); 
    $b = count($b); 

    if($a == $b) { 
     return 0; 
    } 

    return ($a > $b) ? -1 : 1; 
} 

uasort($array, 'sortByCount');