e can be of any type and the type of symbolic name and the corresponding expression must match.
A symbolic name can be used to represent the real part, imaginary part, or both parts of a complex constant.
A constant expression is made up of explicit constants and parameters and the FORTRAN operators. See "Constant Expressions" for more information.
No structured records or record fields are allowed in a constant expression.
Exponentiation to a floating-point power is not allowed, and a warning is issued.
If the type of the data expression does not match the type of the symbolic name, then the type of the name must be specified by a type statement or IMPLICIT statement prior to its first appearance in a PARAMETER statement, otherwise conversion will be performed.
If a CHARACTER statement explicitly specifies the length for a symbolic name, then the constant in the PARAMETER statement can be no longer than that length. Longer constants are truncated, and a warning is issued. The CHARACTER statement must appear before the PARAMETER statement.
If a CHARACTER statement uses *(*) to specify the length for a symbolic name, then the data in the PARAMETER statement are used to determine the length of the symbolic constant. The CHARACTER statement must appear before the PARAMETER statement.
Any symbolic name of a constant that appears in an expression e must have been defined previously in the same or a different PARAMETER statement in the same program unit.