Tiny GPS library

I have to use GPS in my project and I am using arduino uno. While working with TinyGPS library i came across an example and i want to know what this function is doing-->> Serial.print(flat == TinyGPS::GPS_INVALID_F_ANGLE ? 0.0 : flat, 6); Thanks in advance

That function prints a number, after testing whether it is valid.

Look up "C quaternary operator" for an explanation of how it works.