Ros creates subscriber node source code comments___20180422

#include "ros/ros.h"
#include "std_msgs/String.h"

void chatterCallback(const std_msgs::String::ConstPtr& msg)/*Comment0*/
{
  ROS_INFO("I heard [%s]",msg->data.c_str());
}

int main(int argc,char **argv)
{
  ros::init(argc,argv,"example1_b");
  ros::NodeHandle n;
  ros::Subscriber sub = n.subcribe("message",1000,chatterCallback);/*Comment1*/
  ros::spin();
  return 0;  
}
/*___________________________Comment0__________________________________
**This function will be called every time the node receives a message and we can consume or process the data. This instance
**, we output the received data in the command line window.
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*/
/*___________________________Comment1__________________________________
**Create a subscriber and get the message data named message from the topic. set buffer to 1000
**, the callback function for processing the message is messageCallback:
**ros::spin() line is when the node starts to read the topic and the message arrives, the callback function messageCallback is called
**The loop used. When the user presses Ctrl+c, the node exits the loop and the loop ends.
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*/