相关疑难解决方法(0)

当我运行此代码时:

foreach ($tree as $node) {
    echo str_repeat(' ', $node->tree_depth * 4) . $node->id . PHP_EOL;
}

我得到格式良好的文字,如:

Food
 Fruit
   Red
     Cherry
     Strawberry
               Cool
               Not cool
   Yellow
     Banana
 Meat
   Beef
   Pork

但我想创建一个列表<ul><li>...:

我尝试过:

echo '<ul>';
$prev_depth = 0;
foreach($table->fetchTree() as $row) {
    if ($row->tree_depth > $prev_depth) {
        echo '<li><ul>';
    } else if ($row->tree_depth < $prev_depth) {
        echo '</li></ul>';
    }
    echo '<li>' . $row->name . '</li>';
    $prev_depth = $row->tree_depth;
}
echo '</ul>';

但我有一些额外的ul标签等等.我失去了2天,如果你能帮助我,请在这里发帖...