LiteralNull

A literal null specifies the lack of a value.

Description

A literal null is used to represent null, i.e., the absence of a value.

Attributes

No additional attributes.

Associations

No additional associations.

Constraints
No additional constraints.

Additional Operation

  1. The query isComputable() is redefined to be true.

    LiteralBoolean::isComputable(): Boolean; isComputable = true

  2. The query isNull() returns true. LiteralNull::isNull() : Boolean; isNull = true

Semantics

LiteralNull is intended to be used to explicitly model the lack of a value.

Notation

Notation for LiteralNull varies depending on where it is used. It often appears as the word ‘null’. Other notations are described for specific uses.