how to convert php array to xml

I have php array like below

$row = array (
  'name' => 'david',
 'bio' => 'good man'
 );

i want to convert this array to corresponding XML page like scenario below.

 <?xml version="1.0" encoding="UTF-8"?>
 <note>
   <name>david</name>
   <bio>good man</bio>
</note>

anybody please help me to getting a correct solution.

thanks