ROS beginner tutorials:Writing Simple Service and Client (C++) - need explanation [closed]
I'm following the ROS beginner tutorials and currently doing 14.Writing Simple Service and Client (C++) (http://www.ros.org/wiki/ROS/Tutorials/WritingServiceClient%28c%2B%2B%29)
In Section 1.2 Writing the Client Node, the following lines of code have not been explained:
8 if (argc != 3)
9 {
10 ROS_INFO("usage: add_two_ints_client X Y");
11 return 1;
12 }
Can anyone tell me why this comparison is made? Thanks in advance.
P.S.I'm using ROS groovy on Ubuntu 12.10. Following catkin tutorials.