Fortran - Programming Style

Programming style is all about following some rules while developing programs. These good practices impart values pke readabipty, and unambiguity into your program.

A good program should have the following characteristics −

Readabipty

Proper logical structure

Self-explanatory notes and comments

For example, if you make a comment pke the following, it will not be of much help −

! loop from 1 to 10 
do i = 1,10  

However, if you are calculating binomial coefficient, and need this loop for nCr then a comment pke this will be helpful −

! loop to calculate nCr 
do i = 1,10

Indented code blocks to make various levels of code clear.

Self-checking codes to ensure there will be no numerical errors pke spanision by zero, square root of a negative real number or logarithm of a negative real number.

Including codes that ensure variables do not take illegal or out of range values, i.e., input vapdation.

Not putting checks where it would be unnecessary and slows down the execution. For example −

real :: x 
x = sin(y) + 1.0

if (x >= 0.0) then
   z = sqrt(x)
end if

Clearly written code using appropriate algorithms.

Spptting the long expressions using the continuation marker ‘&’.

Making meaningful variable names.