This read-only variable will return the full path ID of the directory that is used by your game to save files to. This directory may or may not be visible to other applications, depending on the platform, and on the HTML5 target it will return an empty string.
NOTE: This variable purely for information and should not be used to get a file path or anything else similar, as it will not work correctly across all platforms.
save_dir = game_save_id;
This will store the directory for saving files to a variable for future use.