
Chapter 2 Building an Object-Oriented Model
Defining operations
An operation is a service that can be requested from an object to effect behavior. It has a name and a list of parameters. An operation is a specification of a transformation or query that an object may be called to execute.
Operation names within a class must be unique. You can give identical names to two or more operations only if they exist in different classes.
Operation properties
An operation has the following properties:
Property
Parent
Name
Code
Comment
Stereotype
Return Type
Visibility
Event
Abstract
Final
Static
Description
Object to which the operation belongs to
Name of the operation
Reference name for the operation
Descriptive comment for the operation
Subclassification of an operation derived from an existing one. Extends the semantics of an operation without changing it's structure
A list of values returned by a call of the operation. If there are no values returned by the operation, the return type value is null
Visibility of the operation, whose value denotes how it may be seen outside its enclosing name space
Significant occurrence that has a location in time and space. An event can trigger a state transition
Indicates that the operation cannot be instantiated and therefore has no direct instances
Indicates that the operation cannot be redefined
Defines the operation as static, meaning it cannot be modified
Maximum length
254
254
254
—
—
—
—
—
—
—
—
An operation definition also includes business rules, and parameters, which are defined on associated property sheets.
67