PHP and Regex - storing a piece of the string for later use in replacement?

Question

Not sure if the subject was clear, hard to describe, easy to show:

I need to convert this:

$text = 'Bunch of text %img_Green %img_Red and some more text here';

to this:

$text = 'Bunch of text <img src="/assets/images/Green.gif" alt="Green" /> <img src="/assets/images/Red.gif" alt="Red" /> and some more text here';

Thanks in advance.

Answer 1

should be

$text = preg_replace('/%img_(\w+)/', '<img src="/assets/images/\1.jpg" alt="\1"/>', $text);

check out the preg_replace doc page on how this is working