Why do we declare constant lat and lon value static const double LONDON_LAT = 51.508131, LONDON_LON = -0.128002;
What does this mean?
https://github.com/mikalhart/TinyGPSPlus/blob/master/examples/FullExample/FullExample.ino
The above link contains the full example program of that line.
This line is from tinygps++ library for extracting the coordinates and displaying in a table format. I'm using arduino uno, GSM module and GPS module to extract the coordinates and transmit it as message. Can anyone explain what dies this constant value mean and why do we use this?
Static variables are allocated storage only once in a program lifetime
The const keyword specifies that a variable's value is constant and tells the compiler to prevent the programmer from modifying it and you can't change const variable's value
and i guess you know double is a data type that can save floating point numbers
that line declare two variables with names LONDON_LAT and LONDON_LON and both of them are in one line
and because london's latitiude and longtitude doesn't change the const keyword is used
also i guess because those variables are constants you can use #define visit https://www.arduino.cc/reference/en/language/structure/further-syntax/define/