How to write Fortran code with few bugs as possible and few debugging time as possible?

[vmagnin]

@CRquantum

So I wonder, do you have easy ways in Fortran to check each pieces of code on the fly?

LFortran will fix that. See the recent post LFortran Minimum Viable Product (MVP)

@CRquantum

But I just too lazy to write drive code every time to check small parts of the code.

I think there is no miracle: either you spend time writing tests, or you spend time debugging… In Test Driven Development the first solution is considered to be best and faster.

Test-driven development

And an advantage of writing tests is that you can more easily optimize or refactor your code: if tests are OK you can feel quite confident that you have not broken your code. Of course you need well designed tests for that.