Class Diagrams l Flashcards
What is an object?
Individuals of a system that have similar characteristics and behaviours
What is a class?
A construction plan for a set of similar objects of a system
What is an attribute?
Structural characteristics of a class
What is an operation?
Behaviour of a class
What does this “+” symbol mean in a class diagram?
public access to the attribute (everybody)
What does this “-“ symbol mean in a class diagram?
private access to the attribute (only the object itself)
What does this “#” symbol mean in a class diagram?
protected access (class itself and subclasses)
What does this “~” symbol mean in a class diagram?
packaged access (classes that are in the same package)
What does this “{readOnly}” mean?
attribute value cannot be changed
What does this “{unique}” mean?
no attribute duplicates are permitted
What does this “{non-unique}” mean?
attribute duplicates are permitted
What does this “{ordered}” mean?
attributes are fixed in order of the values
What does this “{unordered}” mean?
attributes have no fixed order of the values
What does “in” mean?
An input value is expected from this parameter
What does “out” mean?
The parameter has adopted a new value, output
What does “inout” mean?
Combined input/output parameter
Instance variable
Variables that belong to an individual instance or object of a class
What is a class variable?
Variables that belong to the class itself, not to individual instances
What is a class operation?
An operation/method that belongs to the class itself rather to individual instances of that class
What is association?
Possible relationships between instance of classes
What is a multiplicity?
Number of objects that may be associated with exactly one object of the opposite side
What is binary association?
Represents a relationship between exactly two classes
What is a role?
Describes the way in which an object is involved in an association relationship
What is an n-ary association?
Relationship between n classes
Association class
More detailed description of an association
xor relationship
An object of C is in a relationship with either object of A or B but not both
