Information Technology Reference
In-Depth Information
engineering projects can be properly visualized and annotated in a standardized
way, allowing software engineers to better communicate about the various aspects
of the software being designed.
UML was designed to create a standardized modeling language that:
• was expressive and ready-to-use, to provide for the creation of useful, mean-
ingful models;
• was both extensible and able to be specialized to specific projects;
• was programming language independent;
• was development process independent;
• could support higher-level development concepts;
• and integrated various best practices from the field of software engineering.
UML has grown and evolved since its inception. The current version, UML 2.0,
includes 13 different diagram types divided into the following three main groups:
• Structure Diagrams—class, object, component, composite structure, package,
and deployment diagrams
• Behavior Diagrams—use case, activity, and state machine diagrams.
• Interaction
Diagrams—sequence,
communication,
timing,
and
interaction
overview diagrams.
3.2 Object, Classes and Actors
3.2.1 Objects
In the previous chapter, we defined an object as the core unit of a piece of
software, an entity consisting of attributes, methods, an interface, and some unique
identifier. With the use of UML, we are able to create visual representations of
these objects. Figure
3.1
provides us with a familiar example of a UML object
model.
Here we have our
monster_truck
object. Note that the top box shows both
the name and type (instantiating class) of the object. In this case, the object is an
instance of the
Truck
class. In the bottom box, the object's attributes and related
values are displayed.
Fig. 3.1 Monster_truck
object depicted in UML
