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
[…] JavaScript getElementById() Method: This method returns the element that has the ID attribute with the specified value. It is the most used HTML DOM method to manipulate, or get info from, an element on your document. […]