QuickStart Fortran                                  

by Joe Davis

Step-by-step instructions for learning to program in Fortran

 About the language                                                    

Step 1. Download and install G95

• G95 is a free, open-source Fortran 95 compiler.
• Go to http://www.g95.org and download the installer.
• Run the installer and follow the instructions.

Step 2. Write a "hello world" program

• Open Notepad or any other plain text editor.
• Type the following:

program hello
   print *, "Hello, world!"
end

• Save the file as "hello.f95" or something similar.
• Note: files ending in ".f" and ".for" are assumed by G95 to be in the old fixed form (FORTRAN 77), while files ending in ".f90", ".f95", and ".f03" are assumed to be free form. In other words, the above program may not compile if you name it "hello.f" or "hello.for".

Step 3. Run the "hello world" program

• In Windows, bring up a command prompt.
• Navigate to the folder where you installed G95.
• Type the following: g95 -o hello hello.f95
• Run the resulting executable, hello.exe
• Enjoy.

Step 4. Explore the possibilities

• Try something a bit more complicated. Type the following program into a text editor, save it, then compile and run it using G95 as above.

program circle
	real r, area, circumference
	print *, "Enter radius:"
	read *, r
	area = r * r * 3.14159
	circumference = 2 * r * 3.14159
	print *, "Circumference of circle is", circumference
	print *, "Area of circle is", area
end

• Here's another example:

program fact
	integer x, f
	f = 1
	print *, "Enter a number:"
	read *, x
	do 10 j = 1, x
		f = f * j
10	continue
	print *, x, "! =", f
end

 Learning more                                                        

There is a vast amount of information available on the Internet.  Some of the best sources are:

• The Fortran Company - Has a great deal of information on Fortran
• The Fortran Library - Also has lots of Fortran information
• Fortran Tutorials - Links to Fortran tutorials
• Free Fortran Software - Links to free Fortran compilers and other software
• Photran - A Fortran IDE for Eclipse; however, it is currently under development and has no actual documentation

 QuickStart Presentation                                           

Download and view the QuickStart Fortran PowerPoint Presentation.

Back to QuickStart Languages