ROS How to check parameters from previous nodes

Question

Im working on rosparam and I have exercise here to have a node that prints out a number. I can change the number through params. Theres another condition in which the node can run multiple times unless it has different number from previous nodes. Any idea on how to check the parameter of the previous nodes?

Answer 1

ROS params are stored globally on the ros param server. This means that individual nodes don't really own the param value themselves. Instead you should just be pulling params normally with the correct namespace. You can see the difference in namespacing below

std::string global_name, relative_name, other_node_name;
ros::param::get("/global_name", global_name);
ros::param::get("relative_name", relative_name);
ros::param::get("/some_node/param_number", other_node_name);