PHP递归数组循环和格式化

Question

I have some PHP code I've been working on for a good few days now. I'm trying to generate a formatted list of rules from a flat array. I got help here before on how to turn the flat array into a tree array, but I'm having difficulty writing a recursive function that can go through it and successfully break it down at points at such depths where I'd like the rules to be members of an unordered list from the markup that gets printed.

<?php 
$data = array(
    '0'        => 'Introduction',
    '4'        => 'General',
    '4.1'      => 'Chat',
    '4.1.1'    => 'Do',
    '4.1.1.9'  => 'This',
    '4.1.1.10' => 'That',
    '4.1.1.11' => 'Other',
);

$struct = array(
    'children' => array()
);

foreach ($data as $ruleID => $content)
{
    $parent =& $struct;
    foreach (explode('.', $ruleID) as $val)
    {
        if (!isset($parent['children'][$val]))
        {
        $parent['children'][$val] = array(
                'content' => '',
                'children' => array()
            );
        }
        $parent =& $parent['children'][$val];
    }
    $parent['content'] = $content;
}


$out = '';
$rules = array_pop($struct);
format_rule($rules);
var_dump($rules);
echo $out;

function format_rule($arr, $depth=0)
{
    global $out;
    echo "depth: $depth
";
    foreach($arr as $key => $val)
    {
        switch($depth)
        {
            case 0:
                $out .= '<h1>'.$val['content']."</h1><br />
";
                break;
            case 1:
                $out .= '<h2>'.$val['content']."</h2><br />
";
                break;
            case 2:
                $out .= '<h3>'.$val['content']."</h3><br />
";
                break;
            default:
                $out .= '<li>'.$val['content']."</li>
";
                break;
        }
        if(isset($val['children']) && count($val['children']) > 0)
        {
            if($depth > 2)
            {
                $out .= '<ul>';
                format_rule($val['children'], ++$depth);
                $out .= '</ul>';
            }
            else
            {
                format_rule($val['children'], ++$depth);
            }
        }
    }
}

The output at the moment is:

<h1>Introduction</h1><br />
<h1>General</h1><br />
<h2>Chat</h2><br />
<h3>Do</h3><br />
<li>This</li><br />
<li>That</li><br />
<li>Other</li><br />

Which is great, except from my code I'm pretty sure the section under 'Do' should have a <ul> around it.

Answer 1

change your code to :

if($depth >= 2)

note: remember the count starts at 0, not 1.