**Exercise 2.1** ROS 5 days

I don’t understand how do you echo the topic, because we don’t show us how to compile the simple_topic_publisher.cpp. I

hi @leleo1972,

I’m sorry about your confusion. You previous chapter explains how to compile a C++ package. Also, the section titled “Data for Exercise 2.1” also gives further hints.

Could you please let us know exactly where you are stuck so we can better assist you?

Thanks in advance for your response.

By the way, welcome to the community.