rosrun string parameter syntax

I am trying to read an integer parameter as string however ros::param::get() does not read it. std::string my_param; if (ros::param::get("~x", my_param)) { ROS_INFO("value=%s", my_param.c_str()); } rosrun planning planner _x:=12 rosrun planning planner _x:="12" It cannot read parameters either way.