#### 6.1.13 Hollerith constants support

GNU Fortran supports Hollerith constants in assignments, function arguments, and `DATA` and `ASSIGN` statements. A Hollerith constant is written as a string of characters preceded by an integer constant indicating the character count, and the letter `H` or `h`, and stored in bytewise fashion in a numeric (`INTEGER`, `REAL`, or `complex`) or `LOGICAL` variable. The constant will be padded or truncated to fit the size of the variable in which it is stored.

Examples of valid uses of Hollerith constants:

               complex*16 x(2)
               data x /16Habcdefghijklmnop, 16Hqrstuvwxyz012345/
               x(1) = 16HABCDEFGHIJKLMNOP
               call foo (4h abc)

Invalid Hollerith constants examples:

               integer*4 a
               a = 8H12345678 ! Valid, but the Hollerith constant will be truncated.
               a = 0H         ! At least one character is needed.

In general, Hollerith constants were used to provide a rudimentary facility for handling character strings in early Fortran compilers, prior to the introduction of `CHARACTER` variables in Fortran 77; in those cases, the standard-compliant equivalent is to convert the program to use proper character strings. On occasion, there may be a case where the intent is specifically to initialize a numeric variable with a given byte sequence. In these cases, the same result can be obtained by using the `TRANSFER` statement, as in this example.

               INTEGER(KIND=4) :: a
               a = TRANSFER ("abcd", a)     ! equivalent to: a = 4Habcd