How to convert multidimensional recursive array into single dimensional array in PHP?

Question

I have an array which comes out by calling a recursion function on the basis of parent id. This array is an n level multidimensional array. What I want is to break this array into single dimensional, so that every child comes just after their parent. I am using following function to first convert into recursive tree.

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;
    }

This is the array I have.

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
                (
                )

        )
)

This is how I want this.

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
                (
                )

        )
)

There's no one-size-fits-all answer to this in general. In your specific case you could use a recursive function that calls itself on the submenu of a given node if it's not empty. — GordonM
– GordonM, Commented Aug 18, 2015 at 12:24

Chester M · Accepted Answer · 2019-12-09 14:53:12Z

1

It's almost 2020. I know it's a bit late but for those who are googling around: Their answers were close but they're only returning the parent elements. I've tweaked it a little bit to make it work (using 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);

answered Dec 9, 2019 at 14:53

Chester M

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1 Comment

Sunilspr7 Over a year ago

yes its working fine for me. More than 2 level its also working. Thanks

onerror · Accepted Answer · 2015-08-18 12:30:45Z

0

So, I assume you can change your initial function to make an array like the second one... then you should update your function like this:

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;
    }

answered Aug 18, 2015 at 12:30

onerror

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1 Comment

Vikas Badola Over a year ago

This will break sub array into single array , but I need that to be just after their parent.

TeeDeJee · Accepted Answer · 2015-08-18 12:56:14Z

0

This should work. For your use case you don't need a parent_id in your function.

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;
}

answered Aug 18, 2015 at 12:56

TeeDeJee

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1 Comment

Sunilspr7 Over a year ago

its not working for more than two level. for example -

Sathish · Accepted Answer · 2015-08-18 13:22:58Z

Just try this,

$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>';

Output:

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
                (
                )

        )

)

I hope this will help you :)

OpenWebWar · Accepted Answer · 2015-08-18 15:25:26Z

0

(PHP 4 >= 4.0.1, PHP 5)

array_merge_recursive — Merge two or more arrays recursively

`function array_merge_recursive_distinct ( array &$array1, array &$array2 ) { $merged = $array1;

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;
}

}

return $merged; } ?>`

answered Aug 18, 2015 at 15:25

OpenWebWar

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