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.

LNPLS1142Topics

• Syntax

• Semantics

• Examples

• Related Topics

Syntax

LNPLS1023constant_declaration ::=

Description of the illustration constant_declaration.gif

See:

• "datatype ::="

• "expression ::="

Semantics

LNPLS1143constant

Name of the constant that you are declaring.

LNPLS1144datatype

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

LNPLS1145NOT NULL

Imposes the NOT NULL constraint on the constant. For information about this constraint, see "NOT NULL Constraint".

LNPLS1146expression

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

• Example 2-10, "Constant Declarations"

• Example 2-11, "Variable and Constant Declarations with Initial Values"

Related Topics

LNPLS1147In this chapter:

• "Collection Variable Declaration"

• "Record Variable Declaration"

• "%ROWTYPE Attribute"

• "Scalar Variable Declaration"

• "%TYPE Attribute"

LNPLS1148In other chapters:

• "Constant Declarations"

• "Declaring Associative Array Constants"

• "Declaring Record Constants"