Hands-On GUI Programming with C++ and Qt5

Comment

You can add your own comments in the project file to remind yourself of the purpose of adding a specific line of configuration, so that you won't forget why you added a line after not touching it for a while. A comment starts with the hash symbol (#) after which you can write anything since the build system will simply ignore the entire line of text. For example:

# The following define makes your compiler emit warnings if you use 
# any feature of Qt which has been marked as deprecated (the exact warnings 
# depend on your compiler). Please consult the documentation of the 
# deprecated API in order to know how to port your code away from it. 
DEFINES += QT_DEPRECATED_WARNINGS 

You can also add dash lines or use spaces to make your comment ...