UML Tutorial

Unified Modeling Language – UML Tutorial

A Unified Modeling Language is a language for specifying, constructing, visualizing and documenting the software system and its components. UML is a graphical language with a set of rules and semantics. The rules and semantics of a model are expressed in English, in a form known as object constraint language. A model is basically an abstract representation of the system, constructed to understand the system prior to building it.

Goals in designing of UML

• Provide user a ready to use,expressive visual modeling language to develop meaningful models.
• Support high-level development concepts.
• Integrate best practices with methodologies.
• Provide extensibility and specialization mechanism to extend core concepts.

UML diagrams

To design a complex system, single view is insufficient. So, UML has given a set of nearly independent vies of a model. UML defines nine graphical diagrams:

• UML Class diagram
• Usecase diagram
• Behavior diagram
  • Interaction diagram
    • Sequence diagram
    • Collaboration diagram
  • Statechart diagram
  • Activity diagram
• Implementation diagram
  • Component diagram
  • Deployment diagram

UML Class diagram

The UML class  diagram is also referred as object modeling, is a collection of static modeling elements such as classes and their relationships, connected as a graph to each other. Class diagram is a static model i.e., the data won’t change with respect to time.

Class notation

A class is drawn as a rectangle with three components separated by horizontal lines.

• The top name compartment holds the class name
• Middle compartment holds the attributes i.e the properties of the class
• Bottom compartment holds the list of operations.

Class interface notation

Class interface notation is used to describe the visible behavior of the class. Visible behavior of the class may be public, private or protected.

The UML notation for an interface is a small circle with the name of the interface connected to the class and the class that requires the operations in the interface may be attached to a circle by a dashed arrow.