(PHP 5)
DOMDocument::createAttribute — Create new attribute
This function creates a new instance of class DOMAttr. Dieser Knoten wird in Ihrem Dokument nicht sichtbar sein, bis dieser zum Beispiel mit der Funktion DOMNode->appendChild() eingefügt wird.
The name of the attribute.
The new DOMAttr or FALSE if an error occured.
Raised if name contains an invalid character.
A pretty simple example showing how to create attributes and add values to them:
<?php
$doc = new DOMDocument('1.0', 'UTF-8');
$root = $doc->createElement('songs');
$doc->appendChild($root);
for($i=0;$i<10;$i++){
    $root_child = $doc->createElement('song');
    $root->appendChild($root_child);
    
    $root_attr1 = $doc->createAttribute('url');
    $root_child->appendChild($root_attr1);
    
    $root_text = $doc->createTextNode('This is the root element!');
    $root_attr1->appendChild($root_text);
    
    $root_attr2= $doc->createAttribute('artist');
    $root_child->appendChild($root_attr2);
    
    $root_text = $doc->createTextNode('This is the root element!');
    $root_attr2->appendChild($root_text);
    
    $root_attr3 = $doc->createAttribute('track');
    $root_child->appendChild($root_attr3);
    
    $root_text = $doc->createTextNode('This is the root element!');
    $root_attr3->appendChild($root_text);
}
print $doc->saveXML();
?>
This will output as:
<?xml version="1.0" encoding="UTF-8" ?> 
  <songs>
  <song url="This is the root element!" artist="This is the root element!" track="This is the root element!" /> 
  <song url="This is the root element!" artist="This is the root element!" track="This is the root element!" /> 
  <song url="This is the root element!" artist="This is the root element!" track="This is the root element!" /> 
  <song url="This is the root element!" artist="This is the root element!" track="This is the root element!" /> 
  <song url="This is the root element!" artist="This is the root element!" track="This is the root element!" /> 
  <song url="This is the root element!" artist="This is the root element!" track="This is the root element!" /> 
  <song url="This is the root element!" artist="This is the root element!" track="This is the root element!" /> 
  <song url="This is the root element!" artist="This is the root element!" track="This is the root element!" /> 
  <song url="This is the root element!" artist="This is the root element!" track="This is the root element!" /> 
  <song url="This is the root element!" artist="This is the root element!" track="This is the root element!" /> 
  </songs>
If you're looking for an easy way to create an attribute with a certain value, in a similar to createElement() manner, you should use the setAttribute() instead. Documentation and example is available below:
http://php.net/manual/en/domdocument.setattribute.php