Php 使用随机组顺序按组对关联数组排序

我有一个指示组的关联数组键/值。我想对数组进行洗牌，这样组就可以按随机顺序排列，但组中的项目只能在组内进行洗牌。换句话说，我想采取如下措施：

[
    [
        "name" => "Buffy",
        "group" => 1
    ],
    [
        "name" => "Willow",
        "group" => 1
    ],
    [
        "name" => "Xander",
        "group" => 2
    ],
    [
        "name" => "Giles",
        "group" => 2
    ],
    [
        "name" => "Tara",
        "group" => 3
    ],
    [
        "name" => "Angel",
        "group" => 3
    ],
    [
        "name" => "Spike",
        "group" => 3
    ]
]

[
    [
        "name" => "Spike",
        "group" => 3
    ]
    [
        "name" => "Angel",
        "group" => 3
    ],
    [
        "name" => "Tara",
        "group" => 3
    ],
    [
        "name" => "Willow",
        "group" => 1
    ],
    [
        "name" => "Buffy",
        "group" => 1
    ],
    [
        "name" => "Xander",
        "group" => 2
    ],
    [
        "name" => "Giles",
        "group" => 2
    ],
]

然后返回更像这样的内容：

[
    [
        "name" => "Buffy",
        "group" => 1
    ],
    [
        "name" => "Willow",
        "group" => 1
    ],
    [
        "name" => "Xander",
        "group" => 2
    ],
    [
        "name" => "Giles",
        "group" => 2
    ],
    [
        "name" => "Tara",
        "group" => 3
    ],
    [
        "name" => "Angel",
        "group" => 3
    ],
    [
        "name" => "Spike",
        "group" => 3
    ]
]

[
    [
        "name" => "Spike",
        "group" => 3
    ]
    [
        "name" => "Angel",
        "group" => 3
    ],
    [
        "name" => "Tara",
        "group" => 3
    ],
    [
        "name" => "Willow",
        "group" => 1
    ],
    [
        "name" => "Buffy",
        "group" => 1
    ],
    [
        "name" => "Xander",
        "group" => 2
    ],
    [
        "name" => "Giles",
        "group" => 2
    ],
]

我意识到这可能需要两到三种排序，但如果可以用一个

usort

试试看，那就太好了

$groups = [];
foreach (array_unique(array_column($myar, 'group')) as $k) $groups[$k] = rand();
foreach (array_keys($myar) as $k) $myar[$k]['rnd'] = rand();
usort($myar, function($a, $b) use ($groups) {
    if ($gdif = $groups[$b['group']] - $groups[$a['group']]) return $gdif;
    return $b['rnd'] - $a['rnd'];
    });
foreach (array_keys($myar) as $k) unset($myar[$k]['rnd']);

print_r($myar);

使用数据运行，这是一个结果

Array
(
    [0] => Array
        (
            [name] => Buffy
            [group] => 1
        )

    [1] => Array
        (
            [name] => Willow
            [group] => 1
        )

    [2] => Array
        (
            [name] => Angel
            [group] => 3
        )

    [3] => Array
        (
            [name] => Tara
            [group] => 3
        )

    [4] => Array
        (
            [name] => Spike
            [group] => 3
        )

    [5] => Array
        (
            [name] => Giles
            [group] => 2
        )

    [6] => Array
        (
            [name] => Xander
            [group] => 2
        )

)

---

基本上，我的解决方案洗牌输入数组，临时重组输入数组以收集具有相同

组
值的子数组，然后将数据返回到其原始结构

代码：（）

*请注意，
…
（splat操作符）允许
数组_push（）
单独存储所有子数组（每个组内），以生成原始结构

可能的产出：

array (
  0 => 
  array (
    'name' => 'Xander',
    'group' => 2,
  ),
  1 => 
  array (
    'name' => 'Giles',
    'group' => 2,
  ),
  2 => 
  array (
    'name' => 'Willow',
    'group' => 1,
  ),
  3 => 
  array (
    'name' => 'Buffy',
    'group' => 1,
  ),
  4 => 
  array (
    'name' => 'Spike',
    'group' => 3,
  ),
  5 => 
  array (
    'name' => 'Tara',
    'group' => 3,
  ),
  6 => 
  array (
    'name' => 'Angel',
    'group' => 3,
  ),
)

这是一个有趣的问题，但我可以问一下，为什么在示例中有初始结构？如果你想对组进行操作，为什么不使用：[“组”=>1，“名称”=>[“Buffy”，“Willow”]]这段代码也不会随机化组的顺序。@Nick。谢谢错过了。给我几分钟时间，我会解决这个问题和其他一些问题。这些数据是否碰巧来自查询的结果集？