从fetch Array创建无限的ul li标签（用于列表）[关闭]

Question

I'm going to make a unlimited list use li and ul tags from my Array results of PDO(fetched)

my Array :

Array ( 
 [0] => Array ( [category_label] => catLevel4 [category_id] => 22 [category_owner] => 21 ) 
 [1] => Array ( [category_label] => catLevel3 [category_id] => 21 [category_owner] => 20 ) 
 [2] => Array ( [category_label] => catLevel2 [category_id] => 23 [category_owner] => 8 ) 
 [3] => Array ( [category_label] => catLevel2 [category_id] => 24 [category_owner] => 8 ) 
 [4] => Array ( [category_label] => catLevel2 [category_id] => 20 [category_owner] => 6 ) 
 [5] => Array ( [category_label] => catLevel1 [category_id] => 6 [category_owner] => 0 ) 
 [6] => Array ( [category_label] => catLevel1 [category_id] => 7 [category_owner] => 0 ) 
 [7] => Array ( [category_label] => catLevel1 [category_id] => 8 [category_owner] => 0 )
 )

i want :

catLevel1
 catLevel2
  catLevel3
   catLevel4
catLevel1
catLevel1
 catLevel2
 catLevel2

i made a function for convert :

function getCategory($parentCategoryId,$data)
{
    foreach($data as $row){if($row['category_owner']==$parentCategoryId){?>
    <li catId='<?php echo $row['category_id']?>'><a><?php echo $row['category_label'];?></a>
            <ul> 
            <?php getCategory($row['category_id'],$data) ;?>
            </ul>
    </li>
    <?php };}
}

echo getCategory(0,$this->categorysList);

this function is very good working for me , But create null <ul></ul> for all items !

I appreciate your help to build a standard function ;D

Answer 1

You get null <ul> tags, because you hardcode it without any checks, and output in every iteration. Try something like this:

<?php

function getCategory($parentCategoryId, $data) {
    foreach ($data as $row) {
        if ($row['category_owner'] == $parentCategoryId) {
            $str .= '
<li catId="' . $row['category_id'] . '"><a>' . $row['category_label'] . '</a>' . "
";
            $res = getCategory($row['category_id'], $data);
            if ($res) {
                $str .= '
    <ul>' . $res . '</ul>
    ' . "
";
            }
            $str .= '
</li>' . "
";
        }
    }
    return $str;
}

$str = getCategory(0, $data);
echo $str;

?>

So you get output like this:

<li catId="6">
    <a> catLevel1</a>
    <ul>
        <li catId="20">
            <a> catLevel2</a>
            <ul>
                <li catId="21">
                    <a> catLevel3</a>
                    <ul>
                        <li catId="22">
                            <a> catLevel4</a>
                        </li>
                    </ul>
                </li>
            </ul>
        </li>
    </ul>
</li>
<li catId="7">
    <a> catLevel1</a>
</li>
<li catId="8">
    <a> catLevel1</a>
    <ul>
        <li catId="23">
            <a> catLevel2</a>
        </li>
        <li catId="24">
            <a> catLevel2</a>
        </li>
    </ul>
</li>