- var_dump: documentation ( source)
<?php
$div = '<div class="1"><span class="test">text text text</span></div>
<div class="2"><span class="test">text text text</span></div>
<div class="3"><span class="test">text text text</span></div>';
$dom = new \DOMDocument( '1.0', 'UTF-8' );
$dom->loadXML( "<content>{$div}</content>" );
/** @var \DOMNodeList $node */
$list = $dom->getElementsByTagName( 'p' );
/** @var \DOMElement $node */
$node = $list->item( $list->length -1 );
var_dump( $dom->saveXML( $node ) );