PHP | DOMXPath query() Function

<?php

// Create a new DOMDocument instance
$document = new DOMDocument();

// Create a XML
$xml = <<<XML
<?xml version="1.0" encoding="utf-8"?>
<root>
    <content>
        First
    </content>
    <content>
        Second
    </content>
    <content>
        Third
    </content>
</root>
XML;

// Load the XML
$document->loadXML($xml);

// Create a new DOMXPath instance
$xpath = new DOMXPath($document);

// Get the root element
$tbody = $document->getElementsByTagName('root')->item(0);

// Get all the element with name content
$query = '//content';

// Execute the query
$entries = $xpath->query($query);

foreach ($entries as $entry) {
    echo $entry->nodeValue . "<br>";
}
?>

<?php
// Create a new DOMDocument instance
$document = new DOMDocument();

// Create a XML
$xml = <<<XML
<?xml version="1.0" encoding="utf-8"?>
<root>
    <h1>
        Hello
    </h1>
    <h1>
        World
    </h1>
    <h1>
        Foo
    </h1>
    <h1>
        Bar
    </h1>
</root>
XML;

// Load the XML
$document->loadXML($xml);

// Create a new DOMXPath instance
$xpath = new DOMXPath($document);

// Get the root element
$tbody = $document->getElementsByTagName('root')->item(0);

// Get all the element with name h1
$query = '//h1';

// Execute the query
$entries = $xpath->query($query);

// Count the number of headings
echo count($entries);
?>