IF语句中的条件应为标量

Question

我正在编写一个Fortran代码，以计算每门3学分的5门课程的学生的GPA，我尝试使用IF语句，但出现错误

The condition in an IF statement should be scalar

在下面找到我的代码。

program cgpa
implicit none
! This program calculates gp
character, dimension (5) :: grade
character :: name*50
integer :: i
real :: gp, tcp
print *," input student's name"
read*, name
print*, " student's grade"
tcp = 0.0
do i = 1, 5
  read *, grade(i)
 if (grade == "a") then
  tcp = tcp + 15
  end if
  if (grade == "b") then
    tcp = tcp + 12
    else if (grade == 'c') then
      tcp = tcp + 9
    else if (grade == 'd') then
        tcp = tcp + 6

                  else if (grade == 'e') then
                 tcp = tcp + 3

                   else if (grade == 'f') then

                 tcp = tcp + 0
                 else
                   print *, "error type correct grade"
                 end if
   end do
gp = tcp / 15
print *, "dear   " , name, " your GP is" 
print *, gp
print *, " your grades are "
print*, grade
end program cgpa