program create_a_type
! This file: http://ftp.aset.psu.edu/pub/ger/fortran/hdk/Make_a_Type.f90
!
Implicit none
  type chemical_element              ! a user defined data type
    character (len=2) :: symbol
    integer           :: atomic_number
    real              :: atomic_mass
  end type

  type (chemical_element) :: argon, carbon, neon      ! elements
  type (chemical_element) :: Periodic_Table(109)      ! an array
  real                    :: mass                     ! a scalar

  carbon%atomic_mass   = 12.010          ! set a component value
  carbon%atomic_number = 6               ! set a component value
  carbon%symbol        = "C"             ! set a component value

  argon = chemical_element ("Ar", 18, 26.98) ! construct element

  read *, neon                              ! get "Ne" 10 20.183

  Periodic_Table( 5) = argon         ! insert element into array
  Periodic_Table(17) = carbon        ! insert element into array
  Periodic_Table(55) = neon          ! insert element into array

  mass = Periodic_Table(5) % atomic_mass     ! extract component

  print *, mass                         ! gives 26.9799995
  print *, neon                         ! gives Ne 10 20.1830006
  print *, Periodic_Table(17)           ! gives C  6  12.0100002
end program create_a_type