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(g77-295.info)Constants

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Constants
---------

   (Corresponds to Section 4.2 of ANSI X3.9-1978 FORTRAN 77.)

   A "typeless constant" has one of the following forms:

     'BINARY-DIGITS'B
     'OCTAL-DIGITS'O
     'HEXADECIMAL-DIGITS'Z
     'HEXADECIMAL-DIGITS'X

BINARY-DIGITS, OCTAL-DIGITS, and HEXADECIMAL-DIGITS are nonempty
strings of characters in the set `01', `01234567', and
`0123456789ABCDEFabcdef', respectively.  (The value for `A' (and `a')
is 10, for `B' and `b' is 11, and so on.)

   A prefix-radix constant, such as `Z'ABCD'', can optionally be
treated as typeless.  *Note Options Controlling Fortran Dialect:
Fortran Dialect Options, for information on the `-ftypeless-boz' option.

   Typeless constants have values that depend on the context in which
they are used.

   All other constants, called "typed constants", are
interpreted--converted to internal form--according to their inherent
type.  Thus, context is *never* a determining factor for the type, and
hence the interpretation, of a typed constant.  (All constants in the
ANSI FORTRAN 77 language are typed constants.)

   For example, `1' is always type `INTEGER(KIND=1)' in GNU Fortran
(called default INTEGER in Fortran 90), `9.435784839284958' is always
type `REAL(KIND=1)' (even if the additional precision specified is
lost, and even when used in a `REAL(KIND=2)' context), `1E0' is always
type `REAL(KIND=2)', and `1D0' is always type `REAL(KIND=2)'.