我怎样才能排序这个数组由某个键的值

Question

我已阅读array_multisort的文档，但我不知道如何排序这个MD数组由branda值降序。我需要使用递归函数吗？

array(10) { 
    [0]=> array(4) { ["nationality"]=> string(3) "USA" ["branda"]=> int(37) ["brandb"]=> int(491) ["combined"]=> int(9) } 
    [1]=> array(4) { ["nationality"]=> string(5) "India" ["branda"]=> int(32) ["brandb"]=> int(206) ["combined"]=> int(8) } 
    [2]=> array(4) { ["nationality"]=> string(5) "Egypt" ["branda"]=> int(26) ["brandb"]=> int(117) ["combined"]=> int(9) } 
    [3]=> array(4) { ["nationality"]=> string(9) "Indonesia" ["branda"]=> int(18) ["brandb"]=> int(129) ["combined"]=> int(3) } 
    [4]=> array(4) { ["nationality"]=> string(6) "Russia" ["branda"]=> int(64) ["brandb"]=> int(418) ["combined"]=> int(6) } 
    [5]=> array(4) { ["nationality"]=> string(5) "China" ["branda"]=> int(82) ["brandb"]=> int(710) ["combined"]=> int(21) } 
    [6]=> array(4) { ["nationality"]=> string(6) "Turkey" ["branda"]=> int(166) ["brandb"]=> int(536) ["combined"]=> int(28) } 
    [7]=> array(4) { ["nationality"]=> string(11) "Netherlands" ["branda"]=> int(127) ["brandb"]=> int(1498) ["combined"]=> int(23) } 
    [8]=> array(4) { ["nationality"]=> string(6) "Israel" ["branda"]=> int(87) ["brandb"]=> int(1266) ["combined"]=> int(14) } 
    [9]=> array(4) { ["nationality"]=> string(2) "UK" ["branda"]=> int(182) ["brandb"]=> int(2935) ["combined"]=> int(24) } 
    } 

Answer 1

简化@ Hiphop03199代码版本是：

// for acsending sort 
uasort($input_array, function ($a, $b) { return $a['branda'] - $b['branda']; }); 

// for descending sort 
uasort($input_array, function ($a, $b) { return $b['branda'] - $a['branda']; }); 

Answer 2

像这样的工作

$sortingArray = array(); 

foreach($yourArray as $arrayArray){ 
    foreach($arrayArray as $key => $value){ 
     if(!isset($sortingArray[$key])){ 
      $sortingArray[$key] = array(); 
     } 
     $sortingArray[$key][] = $value; 
    } 
} 

$orderby = "branda"; 
array_multisort($sortingArray[$orderby],SORT_DESC,$yourArray); 
var_dump($yourArray); 

Answer 3

我会uasort做（）https://secure.php.net/manual/en/function.uasort.php：

uasort($input_array, function ($i, $j) { 
    $a = $i['branda']; 
    $b = $j['branda']; 
    if ($a == $b) return 0; 
    elseif ($a > $b) return 1; 
    else return -1; 
}); 

注：此代码块将修改 “$ input_array”，当它运行。