PHP json_encode中文乱码问题的解决办法

function _encode($arr)
{
  $na = array();
  foreach ( $arr as $k => $value ) { 
    $na[_urlencode($k)] = _urlencode ($value); 
  }
  return addcslashes(urldecode(json_encode($na)),"\\r\\n");
}

function _urlencode($elem)
{
  if(is_array($elem)){
    foreach($elem as $k=>$v){
      $na[_urlencode($k)] = _urlencode($v);
    }
    return $na;
  }
  return urlencode($elem);
}