preg_match get src of img with specific class

问题

Let's say i have many images in a string and i only want to get the src of the image with a specific class

<img src="image1.jpg"/>
<img src="image2.jpg"/>
<img src="image3.jpg" class="main"/>

I wanted to get the src of the third one, which has a class main. How do i do that?

$pattern = '/< *img[^>]*src *= *["\']?([^"\']*)/i';
preg_match($pattern,$response,$matches);

this one matches all img tags.

回答1:

Don't use a regex to parse HTML. Use DOMDocument instead.

Here's some code:

$dom = new DOMDocument();
@$dom->loadHTML($html);
$xp = new DOMXPath($dom);
$imgs = $xp->query("//img[@class='main']");

$imgs now has a NodeList of images with the main class. (I think - I haven't used DOMXPath much)

来源：https://stackoverflow.com/questions/8867650/preg-match-get-src-of-img-with-specific-class