To have an array of strings of different length, define a type and declare an array of that type.

To have an array of strings of arbitrary length at run-time, you may use deferred-legnth allocatable CHARACTER variables.

program demo_deferred_length

!  An array of "deferred-length" allocatable CHARACTER variables (a
!  Fortran 2003 feature) allows the character length to change at run-time,
!  including automatically through assignment.
call deferred_length()

!  Note that each element of the array has the same length - it is not an
!  array of individually variable length strings. If that's what you want,
!  you have to do it as an array of derived type where the type contains
!  a CHARACTER(:), allocatable component.
call defined_type()

contains

subroutine deferred_length()
   implicit none
character(len=:), dimension(:),  allocatable :: array
integer :: i
integer,parameter :: max_len=14

   !if(.not.allocated(array)) allocate(character(len=max_len) :: array(3))

   ! force all the elements to the same length in a standard-conforming manner
   ! note that this will silently truncate strings longer than the specified length
   array = [character(len=max_len):: 'jones', 'something here','brown']
   !================
   write(*,'(*("[",a,"]":))')array
   write(*,'(*("[",a,"]":))')(trim(array(i)),i=1,size(array))
end subroutine deferred_length

subroutine defined_type()
! to define a type
! and declare an array of that type, e.g.
!
type string
   character(len=:), allocatable :: str
end type string
integer :: i
type(string) :: array(3)

   array(1)%str = 'jones'
   array(2)%str = 'smith'
   array(3)%str = 'brown'
   write(*,'(a)') (array(i)%str,i=1,3)
! or
   array = [string('jones'), string('smith'), string('brown')]
   write(*,'(a)') (array(i)%str,i=1,3)
end subroutine defined_type

end program demo_deferred_length