Associations
Associations
represent relationships between classes and have defined multiplicities at both
ends. On the following example, an owner can own one or many land
parcels, and a land parcel can be owned by one or many owners:
A multiplicity is a constraint on
the number of objects that can be associated with another object. Association
and composition relationships have multiplicities on both sides. The following
is the notation for multiplicities:
· 1—One and only one. Showing this
multiplicity is optional.
· 0..1—Zero or one.
· M..N—From M to N .
· *
or 0..*—From zero
to any positive integer.
· 1..*—From one to any positive integer.