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.
ToDoItemStandard tab.
PropertiesSee Section 18.9.2, “ Parameter Property Toolbar ” and Section 18.9.3, “ Property Fields For Parameter ” below.
DocumentationStandard tab. See Section 13.4, “ Documentation Tab ”.
SourceStandard tab. This contains a declaration for the parameter.
Tagged ValuesStandard 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 upNavigate up through the package structure.
New parameterThis 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. |
New DatatypeThis creates a new Datatype (see Section 16.3, “ Datatype ”) in the namespace of the owner of the operation of the parameter, navigating immediately to the properties tab for that datatype.
New StereotypeThis creates a new Stereotype (see Section 16.6, “ Stereotype ”) for the selected parameter, navigating immediately to the properties tab for that stereotype.
DeleteThis 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 presentation tab or the button 2 pop up menu for the class on the diagram. |
NameText 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. |
StereotypeDrop 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 16.6, “
Stereotype
”).
OwnerText box. Records the operation which contains this parameter.
Button 1 double click on the entry will navigate to the operation.
TypeDrop 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 |
Default ValueText 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 |
KindRadio box, with entries out,
in/out, return,
and in.
out. The parameter is used
only to pass values back from the operation.
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. |
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
|
in. The parameter is used
only to pass values in to the operation.