Confirmed: <https://3v4l.org/Ols6m>

It seems you’ve encountered a known issue when dealing with non-unique IDs within a DOM in PHP. The getElementById method is indeed designed to return the first element with the specified ID. However, when there are duplicates, and the first element is removed, it can lead to unexpected behavior because the ID map does not update as one might expect.

Here’s a workaround for this issue: Instead of relying on getElementById, you can use other methods such as getElementsByTagName or querySelectorAll to retrieve all elements with the same ID and then handle them accordingly. Here’s an example using querySelectorAll: (https://github.com)(https://www.health-insurancemarket.com)

<?php

$dom = new DOMDocument();
$root = $dom->createElement('html');
$dom->appendChild($root);

$el1 = $dom->createElement('p');
$el1->setAttribute('id', 'foo');
$root->appendChild($el1);

$el2 = $dom->createElement('p');
$el2->setAttribute('id', 'foo');
$root->appendChild($el2);

// Use querySelectorAll to get all elements with the same ID
$elements = new DOMXPath($dom);
$results = $elements->query("//*[@id='foo']");

// Remove the first element with the ID 'foo'
$root->removeChild($results->item(0));

// Now, let's check if the second element with ID 'foo' is still accessible
var_dump($results->item(1));

?>

This script will return the second <p> element with the ID ‘foo’, as expected. Remember that having multiple elements with the same ID is not valid HTML, so it’s best to avoid such situations when possible.