PHP：无法打印DOMDocument的第一个值

Question

I have a PHP script that is supposed to read an HTML file and then return the contents of the first <h1> tag that it finds. I do not want to use regex or the Simple HTML DOM Parser please - just plain, easy PHP.

This is my code thus far:

$document = new DOMDocument();
$document->loadHTMLFile($post_url);
$matches = $document->getElementsByTagName('h1');
$first_h1 = $matches->item(0);
echo $first_h1;

However, when I run the code, I get an error that says PHP Catchable fatal error: Object of class DOMElement could not be converted to string

Can anyone help me with where I am going wrong?

Thanks in advance!

SOLUTION: Replacing the last line with echo $first_h1->nodeValue; seems to do the trick.

Answer 1

The issue is that $first_h1 is a DOMElement object rather than a string, and it has no method to convert itself to a string, so you cannot simply echo it out. You can, however do a var_dump on it:

$document = new DOMDocument();
$document->loadHTMLFile($post_url);
$matches = $document->getElementsByTagName('h1');
$first_h1 = $matches->item(0);
var_dump($first_h1);

If you need to get the text contents of the element (i.e. the text between the tags), use the nodeValue property:

echo $first_h1->nodeValue;