返回递归函数的结果

Question

I got a recursive function which currently echo the results. I want this function to return results and loop them with foreach inside markup.

I understand that i should use some kind of iteration for each array to get my desired result but have failed with that. Currently my code look like this(with attempts to iterate):

public static function recursiveChildCategory($categories = array(), $depth = 0, $i = 0) {
    $ca = [];

    // Loop through categories
    foreach($categories as $key => $category){
        echo str_repeat("  ", $depth);
        echo "<a href='".implode('/', $category['breadcrumb'])."'>{$category['title']}</a>";
        echo '<br>';

       $ca[$i] = [
           'id' => $category['id'],
           'title' => $category['title'],
       ];

       if(isset($category['child'])) {
           // Loop
           self::recursiveChildCategory($category['child'], $depth + 1, $i++);
       }
   }
   return $ca;
}

And incoming array to the function:

Array ( 
    [0] => Array ( 
        [id] => 7 
        [title] => Deserts 
        [slug] => deserts 
        [child] => Array ( 
            [0] => Array ( 
                [id] => 8 
                [title] => Space 
                [slug] => space 
                [child] => Array ( 
                    [0] => Array ( 
                        [id] => 
                        [title] => 
                        [slug] => 
                        [child] => Array ( ) 
                    ) 
                ) 
            ) 
        ) 
    ) 
)

Currently it just returns first level of child categories "Deserts", but nothing about "Space".

As desired result i want function to return all categories with $depth and infinite path to multiple child categoires (to do the same work as currently echo doing).

Thanks in advice

Answer 1

Try this and tell me if it's what you are looking for :

The array for my test :

$array = [
    0 => [
        "id" => 7,
        "title" => "Deserts",
        "slug" => "deserts",
        "child" => [
            0 => [
                "id" => 8,
                "title" => "Space",
                "slug" => "space",
                "child" => [
                    0 => [
                        "id" => 9,
                        "title" => "Test",
                        "slug" => "test"
                    ]
                ]
            ]
        ]
    ]    
];

The recursive function :

function recursiveChildCategory($categories, $depth = 0, $ca = []) {
    // Loop through categories
    foreach($categories as $key => $category){
       $ca[$depth] = [
           'id' => $category['id'],
           'title' => $category['title'],
       ];

       if(isset($category['child'])) {
           // Loop
           $ca = recursiveChildCategory($category['child'], $depth + 1, $ca);
       } else {
            break;
       }
   }
   return $ca;
}

Now, how to use it :

$test = recursiveChildCategory($array);
var_dump($test);

And this is the output :

array(3) {
  [0]=>
  array(2) {
    ["id"]=>
    int(7)
    ["title"]=>
    string(7) "Deserts"
  }
  [1]=>
  array(2) {
    ["id"]=>
    int(8)
    ["title"]=>
    string(5) "Space"
  }
  [2]=>
  array(2) {
    ["id"]=>
    int(9)
    ["title"]=>
    string(4) "Test"
  }
}

Here is a link to test it : http://sandbox.onlinephpfunctions.com/

EDIT : I made some modification because in OP example array can have multiple result in first "depth", here is the "new" solution :

The array for test :

$array = [ 
    "0" => 
        [ "id" => 3, "title" => "Subcat", "slug" => "subcat", "child" => 
            [ "0" => 
                [ "id" => 5, "title" => "Subsubcat2", "slug" => "subcat2", "child" => 
                    [ "0" =>
                        [ "id" => "", "title" => "", "slug" =>"", "breadcrumb" => [ "0" => "homeworld", "1" => "cat", "2" => "subcat", "3" => "subcat2" ], "child" => [ ] ] 
                    ]
                ] 
            ]
        ],

    "1" => 
        [ "id" => 4, "title" => "Kalahari", "slug" => "kalahari", "child" => 
            [ "0" => [ "id" => 7, "title" => "deserts", "slug" => "deserts", "child" =>
                [ "0" => 
                    [ "id" => 8, "title" => "Ural", "slug" => "ural", "child" => 
                        [ "0" => [ "id" =>"", "title" =>"", "slug" =>"", "child" =>  [ ] ] ]
                        ]
                    ]
                ]
            ]
        ]
    ];

The function : I just add $ca[$depth][] instead of $ca[$depth]

function recursiveChildCategory($categories, $depth = 0, $ca = []) {
    // Loop through categories
    foreach($categories as $key => $category){
       $ca[$depth][] = [
           'id' => $category['id'],
           'title' => $category['title'],
       ];

       if(isset($category['child'])) {
           // Loop
           $ca = recursiveChildCategory($category['child'], $depth + 1, $ca);
       } else {
            break;
       }
   }
   return $ca;
}

And now the result :

$test = recursiveChildCategory($array);

foreach ($test as $depth => $c) {
    echo "depth : ".$depth."
";
    foreach ($c as $result) {
        echo "Title : ".$result['title']."
";
    }
     echo "=============
";
}

The output is :

depth : 0
Title : Subcat
Title : Kalahari
=============
depth : 1
Title : Subsubcat2
Title : deserts
=============
depth : 2
Title : 
Title : Ural
=============
depth : 3
Title : 
=============

Test here : link