PHP | DOMImplementation createDocumentType() function

The DOMImplementation::createDocumentType() function is an inbuilt function in PHP which is used to create an empty DOMDocumentType object. Entity declarations and notations are not available.

Syntax:

DOMDocumentType DOMImplementation::createDocumentType
( string $qualifiedName = NULL, string $publicId = NULL,
 string $systemId = NULL )

Parameters:This function accepts three parameters as mentioned above and described below:

• $qualifiedName (Optional): It specifies the qualified name of the document type to create.
• $publicId (Optional): It specifies the qualified name of the external subset public identifier.
• $systemId (Optional): It specifies the external subset system identifier.

Return Value: This function returns DOMDocumentType node with its ownerDocument set to NULL.

Exceptions: This function throws DOM_NAMESPACE_ERR, if there is an error with the namespace, as determined by $qualifiedName.

Below given programs illustrate the DOMImplementation::createDocumentType() function in PHP:
Program 1:

<?php

// Creates an instance of the DOMImplementation class
$imp = new DOMImplementation();

// Creates a DOMDocumentType instance
$dtd = $imp->createDocumentType(
'svg:svg', null, 'http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd');

// Get the systemId
echo $dtd->systemId;
?>

Output:

http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd

Program 2:

<?php
// Creates an instance of the DOMImplementation class
$imp = new DOMImplementation();

// Creates a DOMDocumentType instance
$dtd = $imp->createDocumentType('GeeksforGeeks');

// Get the name
echo $dtd->name;
?>

Output:

GeeksforGeeks

Reference: https://www.php.net/manual/en/domimplementation.createdocumenttype.php