Implicit none forces you to declare every variable used in the program. This is useful when writing bug free code. Fortran uses standard mathematical operation techniques. Integer division and real division are separate operations sharing the same operator. Integer division rounds the result to the lower integer.
Real division gives the complete result.
File Processing Input and output files can be used in fortran code. An input file is a collection of data created before program is run with program inputs. An output file contains the output of the program once run. Files must be opened before using. Format Statements Format statements are not required in fortran programs.