MODUL 2

Question 1

what is a model?

Answer 1

an abstraction/simplification of the system it represents

Question 2

what does it mean that a modeling language have a notation?

Answer 2

notation = the elements that make up the language

Question 3

what does it mean that a modeling language have semantics?

Answer 3

semantics = description of what the notation means, captured in meta-model

Question 4

What are the 6 advantages of UML?

Answer 4

1. formal
2. concise
3. comprehensive
4. scaleable
5. lessons learned
6. standard

Question 5

What is an informal language?

Answer 5

A language that does not have a formally defined noation of its elements. ex) nartural language

Question 6

what are some problems when modeling with code?

Answer 6

• focuses only on the software and not the rest of the system
• contains every detail, no abstarction, no bigger picture
• can’t be understood by people who don’t read code
• might not be reusable
  –> only one level of abstraction

Question 7

abstraction (classes)

Answer 7

means that you skip irrelevant details in the description/definition. A class is to only contain relevant information for the context it is to be used in.

Question 8

encapsulation (classes)

Answer 8

enables the class to hide its inner details from the outside world. with this the classes can change internally without it effecting how the class is interacted with. Small changes will not cause the system to break.

Question 9

attributes (classes)

Answer 9

describes the state of an objects

Question 10

operations (classes)

Answer 10

describe what the class can do and which operations it supports/ behaviours it has

Question 11

4 visibility characteristics (classes)

Answer 11

1. public
2. protected
3. package
4. private

Question 12

intitial node and end node (activity)

Answer 12

shows the start and finish of an activity diagram. The activity starts when the initial node becomes active.

Question 13

edges / paths (activity)

Answer 13

shows the flow within an activity, the arrows show in wich directions the flow is going.

Question 14

incoming and outgoing edge (activity)

Question 15

decision and merge (activity)

Answer 15

like an if-else situation shown with a diamond. the path branches and then merges in a second diamond

Question 16

guard condition (activity)

Answer 16

determines which path to take after a decision diamond, should be mutually exclusive

Question 17

activity frame (activity)

Answer 17

contains an activitys actions, optional

Question 18

forks and joins (activity)

Answer 18

used when actions happens in parallell or cocurrently. forks hae outgoing flows and joins have incomming flows.

Question 19

time events

Answer 19

hourglass, represents a wait period or interval

Question 20

recurring time event (activity)

Answer 20

hourglass without an incoming flow/edge

Question 21

call activity node (activity)

Answer 21

shown with an upside-down pitchfork. it calls the activity corresponding to the node name. an action had to be made in to an activity itseld to specify the actions within it

Question 22

object nodes (activity)

Answer 22

can be used to show the data flowing through the activty

Question 23

pins (activity)

Answer 23

shows that an object is input to or output from an action

Question 24

transformation (activity)

Answer 24

can be used when not the whole output object is needed as input fro the next action.

Question 25

signals, receive and send (activity)

Answer 25

represent interaction with external participants, They are messages that can be sent or received

Question 26

interruption regions (activity)

Answer 26

if 2 happens while 1 is taking place, 1 will be interrupted and 2 will become active instead. dotted box and lightning path

Question 27

flow final node (activity)

Answer 27

terminate sits own (branched)path withput ending the whole activity

Question 28

partitions, swimlanes and annotations (activity)

Answer 28

partitions to show which participant is responsible for whisch actions you can show this by swimlanes(columns/rows) or annotations ehere you write it directly in the actions.

Question 29

connectors (activity)

Answer 29

come in pairs and are used to chop the diagram up so that it is easier to read.

Question 30

different ways an activity can start in a diagram (activity)

Answer 30

- the activity starts with a single initial node - the activity starts with by receiving input data - the activity starts in response to a time event - the activity starts as a result of being woken up by a signal

Question 31

inline attributes and associated attributes (classes)

Question 32

what can an attribute contain? (classes)

Answer 32

contains a visibility property, name and type. name is the only mandatory part

Question 33

multiplicity (classes)

Answer 33

allows you to specify that an attribute represents a collection of objects. 1..5, 1..* unique, ordered, not unique

Question 34

ReadOnly property (classes)

Answer 34

the values of the attribute can not be changed once its initial value has been set

Question 35

what can a operation contain?

Answer 35

contains a visibility property, a name, a pair of parentheses with needed parameters and a return type