Question

How do I exactly match multiple instances of img tags? I read up a few tutorials on preg_match yet never really quite understand.

I have this as my base:

<img src="http://example.com/1.png" alt="Example" />

<img class="Class" src="http://example.com/2.jpg" alt="Example 2" />

And I did up a small like regex:

<img (src="|class="Class" src=")http://.+\.(?:jpe?g|png)" alt="

After this, I’m stuck. How do I continue to match all till the end of the both strings?

I found out about the array part on PHP website itself:

preg_match('@^(?:http://)?([^/]+)@i',
    "http://www.php.net/index.html", $matches);
$host = $matches[1];

Using my code, how do I get the image URL, and the alt tag?

Thanks!

Answer 1

For the original question, use preg_match_all() function to get all the matches.

For the second question (“Using my code, how do I get the image URL, and the alt tag?”), basically your regex is correct. However, I would suggest to get the whole <img> tag first, then do another preg_match() to get the href and alt attributes, since their order may vary.

$html = "<img src='test.jpg' alt='aaaaaaaaaaa!'>  adfa <img src='test2.jpg' alt='aaaaaaaaaaa2'>  ";

$pattern = '/<img\s[^>]*>/';
$count = preg_match_all($pattern, $html, $matches, PREG_SET_ORDER);

echo "Found: " . $count . "\n";
if ($count > 0) {
    foreach ($matches as $match) {
        $img = $match[0];
        echo "img: " . $img . "\n";
        if (preg_match("/src=['\"]([^'\"]*)['\"]/", $img, $val)) {  # UPDATE: use () to catch the content of src
            $src = $val[1];      # UPDATE: get the part in ()
        }
        if (preg_match("/alt=['\"]([^'\"]*)['\"]/", $img, $val)) {   # UPDATE
            $alt = $val[1];      # UPDATE
        }

        echo "src = " . $src . ", alt = " . $alt . "\n";
    }
}

---

UPDATE

Answer to your comment.
Sure. Just use a group to catch the part after src=.
I updated the source above and commented with “UPDATE”.