How to change attribute value on a simpleXML element?

I parsed a XML file with SimepleXML:

<element data="abc,def">
 EL
</element>

But now I want to append something to the “data” attribute. Not in the file, but in my variables (in the object structure that I got from simplexml_load_file).

How can I do that?

Answer

Untested, but should work:

$element->attributes()->data = ((string) $element->attributes()->data) . ',ghi';