Why is the pipe not working?

Question

I am stumped as to why a pipe doesn't work.

/(?:<img.*?src=[\'"](.*?)[\'"].*?>)|(http(?:[^\s]*)\.(?:jpg|jpeg|gif|png))/

Here is the full pastebin of the code: http://pastebin.com/J2y8jbsg

For example a link such as:

http://guardianlv.com/wp-content/uploads/2014/03/Robots-The-Possibilities-of-Artificial-Intelligence.jpg

will be captured if the second regex pattern is alone. (http(?:[^\s]*)\.(?:jpg|jpeg|gif|png))

But when I add it with another, as shown initially above and in the pastebin, as a pipe, all I get is an empty array:

Array ( [0] => [1] => )

Can someone explain this? And also a solution would be helpful :) Thank you.

Answer 1

In your first part:

<img.*?src=[\'"](.*?)[\'"].*?>
                 ^  

this is the first capture group. So:

(http(?:[^\s]*)\.(?:jpg|jpeg|gif|png)

is your second capture group. So:

foreach ( $matches[1] as $url ) {

is incorrect. You can use:

foreach ( $matches[2] as $url ) {

or

foreach ( $matches[0] as $url ) {

for the full match.

Demo: https://eval.in/705305

Regex101 demo: https://regex101.com/r/KXjmo3/1