How to convert JSON file to XML format in PHP

$content = file_get_contents('./data.json');

$content = file_get_contents('./data.json');

$data = json_decode($content, true);

$content = file_get_contents('./data.json');

$data = json_decode($content, true);

function xml_encode($data)
{

    $string="";

    foreach($data as $k => $v){
        $string .= "<" . $k . ">";
        //判断是否是数组，或者，对像
        if(is_array($v) || is_object($v)){
            //是数组或者对像就的递归调用
            $string .= xml_encode($v);
        }else{
            //取得标签数据
            $string .=$v;
        }
        $string .= "";  
    }

    return $string;
}

$content = xml_encode($data);

$content = file_get_contents('./data.json');

$data = json_decode($content, true);

function xml_encode($data)
{

    $string="";

    foreach($data as $k => $v){
        $string .= "<" . $k . ">";
        //判断是否是数组，或者，对像
        if(is_array($v) || is_object($v)){
            //是数组或者对像就的递归调用
            $string .= xml_encode($v);
        }else{
            //取得标签数据
            $string .=$v;
        }
        $string .= "";  
    }

    return $string;
}

$content = xml_encode($data);

file_put_contents('./data.xml', $content);