3v4l.org

run code in 300+ PHP versions simultaneously
<?php $dom = new DOMDocument; $dom->loadXML('<schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"/>'); $dummy = new DOMDocument; $dummy->loadXML('<element xmlns="http://www.w3.org/2001/XMLSchema" name="username" type="string"/>'); $dom->documentElement->appendChild($dom->importNode($dummy->documentElement)); echo $dom->saveXML();
Output for 8.1.0 - 8.1.34, 8.2.0 - 8.2.30, 8.3.0 - 8.3.30, 8.4.1 - 8.4.18, 8.5.0 - 8.5.3
<?xml version="1.0"?> <schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"><xsd:element name="username" type="string"/></schema>

preferences:
66.02 ms | 995 KiB | 4 Q