Class Diagram (CD)

Introduction

The class diagram supports UML and OMT notation. This section describes the diagram symbols used when you select OMT notation using Options | Diagram.

Control panel

The following table shows the OMT symbols as they appear in the control panel of the class diagram.

Note: The bold names indicate the symbols that are unique to OMT. This section describes only these OMT symbols. The remaining symbols are the same in OMT and UML and are described in Class Diagram (CD, cad).

Link attribute box

Graphically, a link attribute box is connected to an association (or n-ary association) using an association class connector. Semantically, the association, the link attribute box, and the association class connector are a single model element. The link attribute box allows you to specify attributes that describe the association.

Container class

A container class implements general purpose data structures. It refers to a possible actual implementation of the class. The container class refers to the organization or structure of the data so that algorithms can use it. These data structures are generally part of the library that comes with an object-oriented programming language. A general purpose data structure is an instance of a container class. Possible data structures are sets, bags, dynamic arrays, lists, queues, stacks, dictionaries, associations, and trees. Container classes serve as a framework for organizing collections of other objects.

Association class connector

Association class connectors are similar in OMT and UML, with these differences:

• The notation:

  OMT	UML

• In OMT, an association class connector can connect either an attribute or class to an association. In UML, an association class connector connects a class to an association.

For more information, see Association class connector.

Generalization

Semantically, generalizations are the same in OMT and UML. The only difference is the notation.

For more information, see Generalization.

Multiplicity

Semantically, multiplicity of associations is the same in OMT and UML. The only difference is the notation.

In UML, the multiplicity of the association is always indicated by a multiplicity specification that appears above the association connector.

In OMT, you can add a multiplicity specification after adding the association. For example, to indicate a multiplicity of 2 or more, add the following multiplicity specification to a many association: 2+.

For more information, see Association.