A parameter is a variable that can be passed. In the UML metamodel it
is a sub-class of ModelElement
.
A parameter is represented within the operation declaration in the operation compartment of a class as follows.
name
:
type
name is the name of the parameter.
type is the type (UML datatype, class or interface) of the parameter.
The exception is any parameter representing a return value, whose type only is shown at the end of the operation declaration.
The details tabs that are active for parameters are as follows.
ToDoItem
Standard tab.
Properties
See Section 17.8.2, “Parameter Property Toolbar” and Section 17.8.3, “Property Fields For Parameter” below.
Documentation
Standard tab. See Section 12.5, “Documentation Tab”.
Source
Standard tab. This contains a declaration for the parameter.
Constraints
Standard tab. ArgoUML only supports constraints on Classes and Features (Attributes, Operations, Receptions, and Methods), so this tab is grayed out.
Tagged Values
Standard tab.
In the UML metamodel, Parameter
has the following
standard tagged values defined.
derived
(from the
superclass, ModelElement
). Values
true
, meaning the parameter is
redundant—it can be formally derived from other
elements, or false
meaning it
cannot.
![]() | Caution |
---|---|
A derived parameter is a meaningless concept. |
![]() | Note |
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The UML |
Go
up
Navigate up through the package structure.
Add
parameter
This creates a new parameter for the for the same operation as the current parameter, navigating immediately to the properties tab for that parameter.
![]() | Tip |
---|---|
This is a convenient way to add a series of parameters for the same operation. |
Delete
This deletes the parameter from the model
![]() | Warning |
---|---|
This is a deletion from the model not just the diagram. If desired the whole operation compartment can be hidden on the diagram using the style tab or the button 2 pop up menu for the class on the diagram. |
Name
Text box. The name of the parameter. By convention, the name of a parameter has a leading lower case letter, with words separated by “bumpy caps”.
![]() | Note |
---|---|
The ArgoUML critics do not complain about parameter names that do not have an initial lower case letter. |
Stereotype
Drop down selector. There are no UML standard
stereotypes for Parameter
.
Navigate Stereotype
icon. If a
stereotype has been selected, this will navigate to the
stereotype property panel (see Section 15.4, “Stereotype”).
Owner
Text box. Records the operation which contains this parameter.
Button 1 click on the entry will navigate to the
operation. Button 2 click provides a pop up menu with a single
entry, Open
, which will also navigate to the
operation.
Type
Drop down selector.
The type of this parameter.
This can be any UML Classifier
, although in
practice only
Class
,
DataType
, or
Interface
make any sense.
![]() | Note |
---|---|
A type must be declared (it can be
|
Initial Value
Text box with drop down.
This allows you to set an initial value for the parameter if desired
(this is optional).
The drop down menu provides access to the common
values
0
,
1
,
2
, and
null
.
![]() | Caution |
---|---|
This only makes sense for |
Kind
Radio box,
with entries
in/out
,
in
,
out
, and
return
.
in/out
. The parameter is
used both to pass values in and to pass results back out of
the operation.
![]() | Note |
---|---|
This is the default for any new parameter. |
in
. The parameter is used
only to pass values in to the operation.
out
. The parameter is used
only to pass values back from the
operation.
return
. The parameter is a
return result from the call.
![]() | Note |
---|---|
There is nothing to stop you declaring more than one return parameter (some programming languages support this concept). |
![]() | Tip |
---|---|
The name of the return parameter does not appear on
the diagram, but it is convenient to give it an appropriate
name (such as the default |