Fortran邏輯運算符

試試下麵的例子就明白所有在Fortran語言可用的邏輯運算符：

program logicalOp
! this program checks logical operators
implicit none

   ! variable declaration
   logical :: a, b

   ! assigning values
   a = .true.
   b = .false.

   if (a .and. b) then
      print *, "Line 1 - Condition is true"
   else
      print *, "Line 1 - Condition is false"
   end if

   if (a .or. b) then
      print *, "Line 2 - Condition is true"
   else
      print *, "Line 2 - Condition is false"
   end if

   ! changing values
   a = .false.
   b = .true.

   if (.not.(a .and. b)) then
      print *, "Line 3 - Condition is true"
   else
      print *, "Line 3 - Condition is false"
   end if

   if (b .neqv. a) then
      print *, "Line 4 - Condition is true"
   else
      print *, "Line 4 - Condition is false"
   end if

   if (b .eqv. a) then
      print *, "Line 5 - Condition is true"
   else
      print *, "Line 5 - Condition is false"
   end if

end program logicalOp

當編譯並執行上述程式,將產生以下結果：

Line 1 - Condition is false
Line 2 - Condition is true
Line 3 - Condition is true
Line 4 - Condition is true
Line 5 - Condition is false