Class Diagrams Flashcards
purpose of a class diagram
describe the static structure of a system in a visual form
do class diagrams show the fucntional requirements of a system
no
use case models do this
do class diagrams show how classes interact at run time
no
interaction diagrams used for this
3 parts of a class symbol in order
- class name
- attributes
- operations
what does it mean if an object is persistant
stored, once the program is done, there is still a record of this object
what does it mean if an object is transistory
only in existence while the program is running
what is an attribute of a class
a property that describes a range of values that theobjects of that class may hold
how would you show an attribute’s visibility in the class diagram
+ public
- private
eg + attributeName
how would you show an attribute’s type in the class diagram
:
eg. attributeName: int
how would you show an attribute’s multiplicity in the class diagram
[0…1]
eg attributeName [0..1]: String
how would you show an attribute that has an initial value in the class diagram
=
eg attributeName : int = 5
what are derived attributes
attributes who’s value is a result of a computation based on other attribute values
how to represent derived attributes in class diagrams
/aatributeName
where are operations (methods) of a class listed
just below attributes
how to show association between two classes
draw a line and add association name
