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

Answer 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);

Answer 2

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;
}

Answer 3

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;
}

Answer 4

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 :)

Answer 5

(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;
}
?>`