Question

(Sorry if the title is pretty useless)

I have this function to get the first image from a random post in WordPress. This works great, but now I need it to select a random image from all the matches, rather than the first.
(I’m running this function in a query_posts loop to select the categories)

// Get first image in post
function catch_that_image() {
    global $post, $posts;
    $first_img = '';
    ob_start();
    ob_end_clean();
    $output = preg_match_all('/<img.+src=[\'"]([^\'"]+)[\'"].*>/i', $post->post_content, $matches);
    $first_img = $matches [1] [0];

    //no image found display default image instead
    if(empty($first_img)){
        $first_img = "/images/default.jpg";
    }

    // Or, show first image.
    return $first_img;
}

So, any ideas, links, tips & tricks on how to select a random result from the matches results?

Answer 1

Match everything, and then use array_rand() to get a random match.

Assuming you use the PREG_SET_ORDER flag with preg_match_all then to get a random link.

$randomImage = $matches[array_rand($matches)][0];

It is important to note that array_rand() returns a random key, not a random value.