In
UML diagrams,
data types are model elements that define data
values. You typically use data types to represent primitive types, such as
integer or string types, and enumerations, such as user-defined data types.
A data type is similar to a class; however, instances of data type are
identified only by their value. If two data types have the same value, the
instances are considered identical.
A data type can contain attributes, but only to support the modeling of
structured data types. Instances of structured data types are considered the
same if the following conditions are true:
- The structure of the data types are identical
- The values of the corresponding attributes are identical
By default, when you create a new data type, the compartments for attributes
and operations are hidden.
As the following figure illustrates, a data type artifact is displayed
as a rectangle that contains the name of the data type. The rectangle also
contains the stereotype «data type» and the data type icon.
