PHP:如何按键对数组进行分组？

Question

我有一个 uploads 数组，如下所示:

$uploads[0] = array('type' => 'upload', 'label' => 'blah');
$uploads[1] = array('type' => 'upload', 'label' => 'blah');
$uploads[2] = array('type' => 'upload', 'label' => 'blah');
$uploads[3] = array('type' => 'upload', 'label' => 'foobar');

我想创建这个数组:

$upload_fields = array(
   'blah' => array(
               array('type' => 'upload', 'label' => 'blah')
               array('type' => 'upload', 'label' => 'blah')
               array('type' => 'upload', 'label' => 'blah')
    ),
   'foobar' => array(
               array('type' => 'upload', 'label' => 'foobar')    
    )
);

基本上我想根据标签对数组进行分组。要分组的数组是动态的，否则我可以这样做:

$array_group_1 = array();
$array_group_2 = array();

foreach($uploads as $upload) {
    if($upload['label'] == 'blah') {
        array_push($array_group_1, $upload);
    }  else {
        array_push($array_group_2, $upload);        
    }
}

$upload_fields = array(
    'blah' => $array_group_1,
    'foobar' => $array_group_2
);

但是由于按键是动态的，我怎样才能实现这一点？

Answer 1

这是我想到的:

$uploads[0] = array('type' => 'upload', 'label' => 'blah');
$uploads[1] = array('type' => 'upload', 'label' => 'blah');
$uploads[2] = array('type' => 'upload', 'label' => 'blah');
$uploads[3] = array('type' => 'upload', 'label' => 'foobar');

foreach($uploads as $u){
    $upload_fields[$u['label']][] = $u;
}

echo '<pre>',print_r($upload_fields),'</pre>';