do while（〜の間繰り返す）構造の例

  do while(条件)

    ...
  end do

または

  do
    if(否定条件) exit

    ...
  end do

例．階乗の計算プログラム

program main
  !
  ! Sample programf for DO ... END_DO iteration
  ! Cal. of N!=N*(N-1)*...*1
  !  
  implicit none
  integer :: n
  integer :: factorial,counter

  write(*,*) 'Input N'
  write(*,*) 'N = ?'
  read(*,*) n

  factorial=1
  counter=n

  do while(counter>0)
    factorial=factorial*counter
    counter=counter-1
  end do

  write(*,*) factorial

end program main

例．階乗の計算プログラム（その２）

program main
  !
  ! Sample programf for DO ... END_DO iteration
  ! Cal. of N!=N*(N-1)*...*1
  !  
  implicit none
  integer :: n
  integer :: factorial,counter

  write(*,*) 'Input N'
  write(*,*) 'N = ?'
  read(*,*) n

  factorial=1
  counter=n

  do
    if(counter==0) exit
    factorial=factorial*counter
    counter=counter-1
  end do

  write(*,*) factorial

end program main

実行結果