Question

I am trying to turn flat mysql rows into a tree structure. Here is the id’s of the categories and Sub categories

Array
(
[50] => Array
(
[70] => Array
(
[0] => Array
(
[73] => Array
(
[80] => Array
(
)

                            )

                        [74] => Array
                            (
                            )

                        [75] => Array
                            (
                            )

                    )

            )

        [71] => Array
            (
                [0] => Array
                    (
                    )

            )

        [72] => Array
            (
                [0] => Array
                    (
                    )

            )

        [73] => Array
            (
                [0] => Array
                    (
                        [80] => Array
                            (
                            )

                    )

            )

        [74] => Array
            (
                [0] => Array
                    (
                    )

            )

        [75] => Array
            (
                [0] => Array
                    (
                    )

            )

        [80] => Array
            (
                [0] => Array
                    (
                    )

            )

    )

[51] => Array
    (
        [76] => Array
            (
                [0] => Array
                    (
                        [77] => Array
                            (
                            )

                    )

            )

        [77] => Array
            (
                [0] => Array
                    (
                    )

            )

        [78] => Array
            (
                [0] => Array
                    (
                        [79] => Array
                            (
                                [81] => Array
                                    (
                                    )

                            )

                    )

            )

        [79] => Array
            (
                [0] => Array
                    (
                        [81] => Array
                            (
                            )

                    )

            )

        [81] => Array
            (
                [0] => Array
                    (
                    )

            )

    )

)

I wan the output in this way

 <ul id="red" class="treeview-famfamfam">
    <li>50
        <ul> <li> 70 
                <ul><li> 73 <ul> 
                                <li> 80</li></ul>
                    </li>
                    <li> 74</li>
                    <li>75 </li>
                    </ul>
            </li>
            <li>71</li>
            <li> 72</li>
            </ul>
            </li>

BAsically i need to build a tree with categories sub categories sub sub …. categoreis etc.
Thanks in advance

Answer 1

Edited: OK. I spent half a day on this. I’m sorry to tell you this, but you’ll have to change the definition of your array. Instead of an empty array for the leaf nodes, use a non-array value that has any value… Like this:

$ar=array("50" => array ( "70" => array ( "0" => array("35" => "leaf"),"3"=>"leaf" ) ) );

Then use this:

function MakeTree($array){
    $return="";

        if(!is_array($array)) return;
        while($member=current($array)){     

                $return.="<li>".key($array);
                $return.="<ul>".MakeTree($member)."</ul></li>";

            next($array);           
         }       
        return $return;
    }

    $ar=array("50" => array ( "70" => array ( "0" => array("35" => "leaf"),"3"=>"leaf" ) ) );
    echo(MakeTree($ar));

I don’t know why, but if the leaf node has null or empty array value, it doesn’t get accessed by next($array). Even if it is an empty string, so “35”=>”” won’t work.

If you don’t use next() and current() you can’t use key(), so a change in the structure is inevitable.