The order in which expressions are evaluated

The following table gives a comparison between operators in Pascal and FORTRAN.

	Pascal	FORTRAN
arithmetic operators
- raising to a power		**
- multiplication	*	*
- division	/	/
- division of integers	div, mod
- addition	+	+
- subtraction	-	-
relational operators
- smaller	$<$	.lt.
- greater or equal	$<=$	.le.
- greater	$>$	.gt.
- greater or equal	$>=$	.ge.
- equal	=	.eq.
- not equal	$<>$	.ne.
logical operators
- not	not	.not.
- and	and	.and.
- or	or	.or.

The order in which expressions are evaluated is as follows:

1. **
2. * and /
3. + and -
4. .lt., .le., .eq., .ne., .ge. and .gt.
5. .not.
6. .and.
7. .or.

Within each level evaluation is performed from left to right.
The order of evaluation can be changed by using semicolons.
Example:

      program order
      implicit none
      integer n, nmax
      logical conv, result
      conv = .true.
      n = 5
      nmax = 20
      result = .not. conv .and. 2*n .lt. nmax
      print *, 'result = ', result
      end

If we execute the program above the expression is evaluated as follows:

1. 2*n which gives r1 = 10
2. r1 .lt. nmax, which gives r2 = .true.
3. .not. conv, which gives r3 = .false.
4. r3 .and. r2, which gives: .false.

The program will print: result = .false.