@robkk
Thanks for your support!
sorry, it will display all topic.It doesn’t filter topic.
Thank you for helping me. It worked !
@robkk
sorry,I think I wasn’t explain clearly.I want it ” If forum doesn’t has description then do something” in content-single-forum.php and display below breadcrumb. I try to run your script but it doesn’t work, no matter forum has or not it always echo “yes”.