Object diagram

A correlated set of object diagrams provides insight into how an arbitrary view of a system is expected to evolve over time.

The use of object diagrams is fairly limited, namely to show examples of data structure.

"The latest UML 2.5.1 specification does not explicitly define object diagrams,[4] but provides a notation for "instances" of classifiers.

Only aspects of current interest in a model are typically shown on an object diagram.

This can show an object's classifier (e.g. an abstract or concrete class) and instance name, as well as attributes and other structural features using slots.

In the second diagram, at a slightly later point in time, the IndependentVariable and DependentVariable objects are the same, but the slots for the val attribute have different values.

Other UML entities, such as an aggregation or composition symbol (a diamond) may also appear on an object diagram.

Example of an object diagram.
Initially, when n=2, and f(n-2) = 0, and f(n-1) = 1, then f(n) = 0 + 1 = 1.
After the first iteration, when n = 3, and f(n-2) = 1, and f(n-1) = 1, then f(n) = 1 + 1 = 2.
After several more iterations, when n = 7, and f(n-2) = 5, and f(n-1) = 8, then f(n) = 5 + 8 = 13.