php html分类树,多维数组分类树 组合html树的问题？（递归）

数组结构是这样的：

然后组装成html结构的方法如下：

function creatHtmlTree($tree)

{

static $htmlTree;

$htmlTree .= '

• ';

foreach ($tree as $key => $value) {

$htmlTree .= "

{$value['name']} Goes somewhere";

if (isset($value['childs']) && is_array($value['childs'])) {

$html = creatHtmlTree($value['childs']);

$htmlTree .= $html;

}

$htmlTree .= "

";

}

$htmlTree .= "

";

return $htmlTree;

}

但是实际上输出的结果是错误的：

自己猜想，一定是自己的递归逻辑有问题，但是实在是想不明白问题到底出在哪里。所以还请帮忙看下，那段递归代码有什么问题

另外贴出完整的测试代码：

$data[] =array('id'=>1,'parentid'=>0,'name'=>'中国');

$data[] =array('id'=>2,'parentid'=>0,'name'=>'美国');

$data[] =array('id'=>3,'parentid'=>0,'name'=>'韩国');

$data[] =array('id'=>4,'parentid'=>1,'name'=>'北京');

$data[] =array('id'=>5,'parentid'=>1,'name'=>'上海');

$data[] =array('id'=>6,'parentid'=>1,'name'=>'广西');

$data[] =array('id'=>7,'parentid'=>6,'name'=>'桂林');

$data[] =array('id'=>8,'parentid'=>6,'name'=>'南宁');

$data[] =array('id'=>9,'parentid'=>6,'name'=>'柳州');

$data[] =array('id'=>10,'parentid'=>2,'name'=>'纽约');

$data[] =array('id'=>11,'parentid'=>2,'name'=>'华盛顿');

$data[] =array('id'=>12,'parentid'=>3,'name'=>'首尔');

/**格式化数组输出**/

function p($arr)

{

echo "

";

echo '========================开始========================';

echo "";

if( $arr ){

print_r($arr);

} else {

echo '此值为空';

}

echo "";

echo '========================结束========================';

echo "

";

}

/**

* 多维数组树形结构

*/

function tree($data, $pid = 0)

{

// static $html = '';

// $html .= '

• ';

$children = [];

// p($data);

foreach ($data as $key => $value) {

if ($value['parentid'] == $pid) {

// $html .= '

';

$children[] = $value;

}

}

if (empty($children)) {

return null;

}

foreach ($children as $key => $value) {

$chid = tree($data, $value['id']);

if ($chid != null) {

$children[$key]['childs'] = $chid;

}

}

// $html .= '

';

return $children;

}

function creatHtmlTree($tree)

{

static $htmlTree;

$htmlTree .= '

• ';

foreach ($tree as $key => $value) {

$htmlTree .= "

{$value['name']} Goes somewhere";

if (isset($value['childs']) && is_array($value['childs'])) {

$html = creatHtmlTree($value['childs']);

$htmlTree .= $html;

}

$htmlTree .= "

";

}

$htmlTree .= "

";

return $htmlTree;

}

$tree = tree($data);

$htmlTree = creatHtmlTree($tree);

p($tree);

p($htmlTree);