PHP operation XML Related issues

PHP Operational XML issues
I use PHP to generate XML as follows

PHP Code

  
  $xml = '
  
   . ' \ r \ n "; $xml. =
  
  
   
   ". " \ r \ n "; $xml. =" \ T ". '
   
   
    
    '. www.163.com.
   
   ' \ r \ n "; foreach (Array () as $value) {   $xml. =" \ t ".
   
   
    
    '. $value.
   
   ' \ r \ n ";} $xml. = '
  
  . ' \ r \ n "; $sxe = new SimpleXMLElement ($xml); $sxe->asxml (APPPATH. ' User.xml ');

Generated the User.xml file, I want to add one now:
John doe
How to add Ah, the front with "\ T", followed by "\ r \ n"?

Thank you ~

------Solution--------------------

PHP Code

$sxe = new SimpleXMLElement ($xml), $sxe->addchild (' username ', ' John Doe '); $sxe->asxml (APPPATH ' user.xml ');
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