PHP | DOMNode isDefaultNamespace() Function

The DOMNode::isDefaultNamespace() function is an inbuilt function in PHP which is used to check if the specified namespaceURI is the default namespace or not.

Syntax:

bool DOMNode::isDefaultNamespace( string $namespaceURI )

Parameters: This function accepts a single parameter $namespaceURI which holds the namespace URI.

Return Value: This function return TRUE if namespaceURI is the default namespace, FALSE otherwise.

Below examples illustrate the DOMNode::isDefaultNamespace() function in PHP:

Example 1:

<?php

// Create a new DOMDocument
$dom = new DOMDocument();

// Create a paragraph element with a namespace
$p_element = $dom->createElementNS(
    'my_namespace', 'p', 'GeeksforGeeks');

// Append the child to DOMDocument
$dom->appendChild($p_element);

// Check if the namespace is default or not
if($dom->isDefaultNamespace('my_namespace')) {
    echo 'Yes, my_namespace is the default namespace.';
}
?>

Output:

Yes, my_namespace is the default namespace.

Example 2:

<?php

// Create a new DOMDocument
$dom = new DOMDocument();

// Create a paragraph element with a namespace
$p_element = $dom->createElementNS(
    'my_namespace', 'p', 'GeeksforGeeks');

// Append the child to DOMDocument
$dom->appendChild($p_element);

// Check if the namespace is default or not
if(!$dom->isDefaultNamespace('some_other_namespace'))
{
    echo 'No, some_other_namespace is not'
                         . ' default namespace.';
}
?>

Output:

No, some_other_namespace is not the default namespace.

Reference: https://www.php.net/manual/en/domnode.isdefaultnamespace.php