13.14 Constant Declaration

A constant holds a value that does not change. A constant declaration specifies the name, data type, and value of the constant and allocates storage for it. The declaration can also impose the NOT NULL constraint.

Topics

Syntax

Semantics

constant_declaration

constant

Name of the constant that you are declaring.

datatype

Data type for which a variable can be declared with an initial value.

NOT NULL

Imposes the NOT NULL constraint on the constant.

For information about this constraint, see "NOT NULL Constraint".

expression

Initial value for the constant. expression must have a data type that is compatible with datatype. When constant_declaration is elaborated, the value of expression is assigned to constant.

Examples