Fortran/Fortran structure and style

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[edit] Style

Older versions of Fortran had strict guidelines on how a program was formatted. However new versions, especially Fortran 90 and above have modernized, allowing more flexability.

It has become a bit customary, though completely unnecessary to put fortran commands in ALL CAPS in order to make the program easier to read.

PROGRAM test
IMPLICIT NONE
INTEGER four
four = 4
WRITE (*,*) four
END PROGRAM

Whitespace and empty lines usually won't matter in F90 or above, but in rare cases errors will pop up. However, unlike many other languages such as C, C++, and Java, the line delimiter ';' is optional, so each line of code may stay on its own line!

[edit] Structure

• There is a GOTO command, but don't use it too much.
• Use DO loops early and often.
• Encapsulate your code into functions and subroutines making it easier to program at higher levels, and allowing others to understand whats going on.
• Comment your code well. Don't comment every line, but explain how everything works.