如何在PHP中将多维递归数组转换为一维数组

Question

我有一个数组，它通过调用基于父id的递归函数出来。这个数组是一个n级多维数组。我想要的是把这个数组分解成单维的，这样每个子元素就在它们的父元素之后。我使用下面的函数首先转换成递归树。

function formatTree($tree, $parent){
        $tree2 = array();
        foreach($tree as $i => $item){
            if($item['cat_parent_id'] == $parent){
                $tree2[$item['cat_id']] = $item;
                $tree2[$item['cat_id']]['submenu'] = formatTree($tree, $item['cat_id']);
            } 
        }
        return $tree2;
    }

这是我的数组。

Array
(
    [58] => Array
        (
            [cat_id] => 58
            [cat_name] => Desserts
            [cat_parent_id] => 0
            [submenu] => Array
                (
                    [535] => Array
                        (
                            [cat_id] => 535
                            [cat_name] => dessert child
                            [cat_parent_id] => 58
                            [submenu] => Array
                                (
                                )
                        )
                )
        )
    [56] => Array
        (
            [cat_id] => 56
            [cat_name] => Biryani & Rice
            [cat_parent_id] => 0
            [submenu] => Array
                (
                )
        )
)

这就是我想要的。

Array
(
    [0] => Array
        (
            [cat_id] => 58
            [cat_name] => Desserts
            [cat_parent_id] => 0
            [submenu] => Array
                (
                )
        )
    [1] => Array
                    (
                        [cat_id] => 535
                        [cat_name] => dessert child
                        [cat_parent_id] => 58
                        [submenu] => Array
                            (
                            )
                    )    
    [2] => Array
        (
            [cat_id] => 56
            [cat_name] => Biryani & Rice
            [cat_parent_id] => 0
            [submenu] => Array
                (
                )
        )
)

Answer 1

快2020年了。我知道这有点晚了，但对于那些正在搜索的人来说:他们的答案很接近，但他们只返回父元素。我已经稍微调整了一下，使它工作(使用array_merge)。

function array_single_dimensional($items)
{
    $singleDimensional = [];
    foreach ($items as $item) {
        $children =  isset($item['children']) ? $item['children'] : null; //temporarily store children if set
        unset($item['children']); //delete children before adding to new array
        $singleDimensional[] = $item; // add parent to new array
        if ( !empty($children) ){ // if has children
            //convert children to single dimensional
            $childrenSingleDimensional = array_single_dimensional($children);
            //merge the two, this line did the trick!
            $singleDimensional = array_merge($singleDimensional, $childrenSingleDimensional); 
        }
    }
    return $singleDimensional;
}
$singleDimensionalArray = array_single_dimensional($multidimensionalArray);

Answer 2

所以，我假设你可以改变你的初始函数，使一个数组像第二个…然后你应该像这样更新你的函数:

function formatTree($tree, $parent){
        $tree2 = array();
        foreach($tree as $i => $item){
            if($item['cat_parent_id'] == $parent){
                $item['submenu'] = array();
                $tree2[] = $item;
                formatTree($tree, $item['cat_id']);
            } 
        }
        return $tree2;
    }

Answer 3

应该可以。对于您的用例，您不需要在函数中使用parent_id。

function formatTree($tree){
  $tree2 = array();
  foreach($tree as $i => $item){
    $submenu = $item['submenu'];
    unset($item['submenu']);  //clear submenu of parent item
    $tree2[] = $item;
    if(!empty($submenu)){
      $sub = formatTree($submenu); //submenu's return as array in array
      $tree2[] = $sub[0]; // remove outer array
    }
  }
  return $tree2;
}

Answer 4

试试这个，

$array = Array
(
    "58" => Array
    (
        "cat_id" => 58,
        "cat_name" => "Desserts",
        "cat_parent_id" => 0,
        "submenu" => Array
        (
            "535" => Array
            (
                "cat_id" => 535,
                "cat_name" => "dessert child",
                "cat_parent_id" => 58,
                "submenu" => Array
                ()
            )
        )
    ),
    "56" => Array
    (
        "cat_id" => 56,
        "cat_name" => "Biryani & Rice",
        "cat_parent_id" => 0,
        "submenu" => Array
        ()
    )
);
function singledimensional($array)
{
    $res = array();
    foreach ($array as $i => $item) {
        $temparr = $item;
        $item['submenu'] = array();
        $res[] = $item;
        if (!empty($temparr['submenu']) ){
              $child = singledimensional($temparr['submenu']);
              $res[] =  $child[0];
        }
    }
    return $res;
}
    echo '<pre>';
    print_r(singledimensional($array));
    echo '</pre>';

输出:

Array
(
    [0] => Array
        (
            [cat_id] => 58
            [cat_name] => Desserts
            [cat_parent_id] => 0
            [submenu] => Array
                (
                )
        )
    [1] => Array
        (
            [cat_id] => 535
            [cat_name] => dessert child
            [cat_parent_id] => 58
            [submenu] => Array
                (
                )
        )
    [2] => Array
        (
            [cat_id] => 56
            [cat_name] => Biryani & Rice
            [cat_parent_id] => 0
            [submenu] => Array
                (
                )
        )
)

我希望这对你有帮助:)

Answer 5

(php4>= 4.0.1, php5)

array_merge_recursive -递归合并两个或多个数组

' function array_merge_recursive_distinct (array &$array1, array &$array2){

foreach ( $array2 as $key => &$value )
{
  if ( is_array ( $value ) && isset ( $merged [$key] ) && is_array (     $merged [$key] ) )
  {
    $merged [$key] = array_merge_recursive_distinct ( $merged [$key],   $value );
}
else
{
  $merged [$key] = $value;
}

}

返回$合并;}div ?>