根据 2 个参数对对象数组进行分组和排序

Question

我有一组对象，我想根据一个属性对其进行排序，然后根据另一个属性进行“分组”。在下面的示例中，我希望它们根据 $sequence 排序，并根据 $artist 分组。

// 我的类的精简版本：

<?php
class myClass
{
    public $sequence;
    public $artist;

    function __construct($sequence,$artist)
    {
        $this->sequence=$sequence;
        $this->artist=$artist;
    }

    static function cmp_myclass_sequence($a, $b)
    {
        $a_seq = $a->sequence;
        $b_seq = $b->sequence;
        if ($a_seq == $b_seq) {
            return 0;
        }
        return ($a_seq > $b_seq) ? +1 : -1;
    }
    static function cmp_myclass_artist($a, $b)
    {
        $a_art = strtolower($a->artist);
        $b_art = strtolower($b->artist);
        if ($a_art == $b_art) {
            return 0;
        }
        return ($a_art > $b_art) ? +1 : -1;
    }
}

//some objects of my class which am using for testing :

$myObj1 = new myClass(1,'A');
$myObj2 = new myClass(1,'B');
$myObj3 = new myClass(1,'C');
$myObj4 = new myClass(2,'A');
$myObj5 = new myClass(2,'B');
$myObj6 = new myClass(2,'C');
$myObj7 = new myClass(4,'A');
$myObj8 = new myClass(5,'A');
$myObj9 = new myClass(3,'B');
$myObj10 = new myClass(3,'G');
$myObj11= new myClass(3,'A');

$myArr=array($myObj1,$myObj2,$myObj3,$myObj4,$myObj5,$myObj6,$myObj7,$myObj8,$myObj9,$myObj10,$myObj11);

echo "My Array Before sort : <br>";
foreach ($myArr as $obj){ print_r($obj); echo "<br>"; }

usort($myArr, array("myClass", "cmp_myclass_sequence"));
//usort($myArr, array("myClass", "cmp_myclass_artist"));


echo "My Array AFTER sort : <br>";
foreach ($myArr as $obj){ print_r($obj); echo "<br>";}

?>

类中的两个排序函数 cmp_myclass_sequence 和 cmp_myclass_artist 各自都能很好地工作。但我不确定如何以这种方式分组数组： 所有 A 级艺术家都排在第一位，然后是 B 级艺术家，依此类推。 在 A 艺术家中，对象应按该对象的序列 int 排序。

简而言之，这就是我正在寻找的结果：

/*
My Array AFTER sort : 

myClass Object ( [sequence] => 1 [artist] => A )
myClass Object ( [sequence] => 2 [artist] => A )
myClass Object ( [sequence] => 3 [artist] => A )
myClass Object ( [sequence] => 4 [artist] => A )
myClass Object ( [sequence] => 5 [artist] => A )
myClass Object ( [sequence] => 1 [artist] => B )
myClass Object ( [sequence] => 2 [artist] => B )
myClass Object ( [sequence] => 3 [artist] => B )
myClass Object ( [sequence] => 1 [artist] => C )
myClass Object ( [sequence] => 2 [artist] => C )
myClass Object ( [sequence] => 3 [artist] => G ) 
*/

Answer 1

您可以使用茴香酒好东西来做到这一点：

$result = Arrays::sort($arr, Comparator::compound(
    Comparator::compareBy('artist'),
    Comparator::compareBy('sequence')
));

http://ouzo.readthedocs.org/en/latest/utils/comparators.html

Answer 2

您可以使用一个比较函数轻松完成此操作：

function sort_c_arr($item_1, $item_2)
{
   if($item_1->artist != $item_2->artist)
   {
      return strcmp($item_1->artist, $item_2->artist);
   }
   return $item_1->sequence - $item_2->sequence;
}
// ...
usort($arr, 'sort_c_arr');

Answer 3

像这样的比较函数怎么样：

function cmp_myclass_artist_then_sequence($a, $b) {
    $a_art = strtolower($a->artist);
    $b_art = strtolower($b->artist);
    if ($a_art == $b_art) {
        return cmp_myclass_sequence($as, $b);
    }
    return ($a_art > $b_art) ? +1 : -1;
}

这样您就开始按艺术家进行比较，如果艺术家相同，则按顺序进行比较。我认为应该有效。