Fortran - do while Loop Construct

It repeats a statement or a group of statements while a given condition is true. It tests the condition before executing the loop body.

Syntax

do while (logical expr) 
   statements
end do

Flow Diagram

Example

program factorial  
implicit none  

   ! define variables
   integer :: nfact = 1   
   integer :: n = 1 
   
   ! compute factorials   
   do while (n <= 10)       
      nfact = nfact * n 
      n = n + 1
      print*,  n, " ", nfact   
   end do 
end program factorial  

When the above code is compiled and executed, it produces the following result −

2             1
3             2
4             6
5            24
6           120
7           720
8          5040
9         40320
10        362880
11       3628800