PHP提取XML有关问题

        http://www.163.com
        PHP
        JAVA
        PYTHON
        jack@sina.com

$arr = array(
   'person_siteurl'=>'http://www.163.com',
   'job_keys'=>'php,java,python',
    'email'=>'jack@sina.com'
)

$arr=(array)simplexml_load_file('user.xml');
$res=array_map(function($param){return is_array($param)?implode(',',$param):$param;},$arr);
print_r($res);