The DOMDocument::getElementById() function is an inbuilt function in PHP which is used to search for an element with a certain id.
Syntax:
DOMElement DOMDocument::getElementById( string $elementId )
Parameters:This function accepts a single parameter $elementId which holds the id to search for.
Return Value: This function returns the DOMElement or NULL if the element is not found.
Below given programs illustrate the DOMDocument::getElementById() function in PHP:
Program 1: In this program we will get the tagname of element with certain id.
<?php   // Create a new DOM Document $dom = new DOMDocument('1.0', 'iso-8859-1');   // Enable validate on parse $dom->validateOnParse = true;   // Create a div element $element = $dom->appendChild(new DOMElement('div'));   // Create a id attribute to div $attr = $element->setAttributeNode(         new DOMAttr('id', 'my_id'));   // Set that attribute as id $element->setIDAttribute('id', true);   // Get the tag name $tagname = $dom->getElementById('my_id')->tagName;   echo $tagname; ?> |
Output:
div // Because id 'my_id' is applied to div tag.
Program 2: In this program we will get the content of element with certain id.
<?php   // Create a new DOM Document $dom = new DOMDocument('1.0', 'iso-8859-1');   // Enable validate on parse $dom->validateOnParse = true;   // Create a div element $element = $dom->appendChild(new DOMElement('div',    'Hey, this is the text content of the div element.'));   // Create a id attribute to div $attr = $element->setAttributeNode(           new DOMAttr('id', 'my_id'));   // Set that attribute as id $element->setIDAttribute('id', true);   // Get the tag content $tagcontent = $dom->getElementById('my_id')->textContent;   echo $tagcontent; ?> |
Output:
Hey, this is the text content of the div element.
Reference: https://www.php.net/manual/en/domdocument.getelementbyid.php
