php - To get value using uri segment -

here, using uri segment getting value url.

http://localhost/project/abc/activity/wise_activity 

here, if want wise_activity, can user

$this->uri->segment(2). 

but if want 7 in below url, how can get?

http://localhost/project/abc/activity/wise_activity?id=7 

you can 7 using method in active record as

 $id=$this->input->get("id");  echo $id; 

read input class