Sequence Diagram

Question 1

What type of UML diagram is a Sequence Diagram?

Answer 1

It is a behavioral UML diagram

Question 2

What does a Sequence Diagram primarily show?

Answer 2

How objects interact and the order of messages exchanged

Question 3

What dimension does the vertical axis represent?

Answer 3

Time (progressing down the page)

Question 4

What dimension does the horizontal axis represent?

Answer 4

The objects involved in the interaction.

Question 5

What are the other term for User?

Answer 5

Actor

Question 6

What does other layer called? ( Interface, Application, Database )

Answer 6

Object

Question 7

How is an Actor (e.g., User) represented?

Answer 7

By a stick figure

Question 8

How is an Object represented?

Answer 8

By a rectangle (box) with a name inside

Question 9

What three key questions does a Sequence Diagram answer?

Answer 9

1. Who talks to whom?
2. In what order?
3. What messages?

Question 10

Does a Sequence Diagram focus on structure or process?

Answer 10

It focuses on the process flow over time.

Question 11

What is a ‘Lifeline’?

Answer 11

A vertical dashed line showing an object’s existence over time.

User        ATM Machine (Interface)
   |                           |
	 |                           |
	 |                           |
	 |                           |

Question 12

What is line for sending request to objects?

Answer 12

Solid line with arrow

\_\_\_\_\_\_\_\_\_\_\_>

Write the function from class diagram with parameter to get full marks

Question 13

What is the line for reply of the request?

Answer 13

Dotted line with arrow
~~~
——>
~~~

Question 14

How to show alternative flow

Answer 14

Draw a rectangle with the text “Alt” at top left

IF card valid  - Request Pin
IF card invalid - Eject Card

Question 15

What will the Alt rectangle become in programming?

Answer 15

If else statement

Question 16

How to divide the alternative flows in the rectangle?

Answer 16

A solid or dotted line

Question 17

What does the length of the status bar indicates?

Answer 17

It indicates the duration of the object’s existence over time.

Known as Status Line / Active Line (Green Bar at Slide)

A rectangle bar that is connected to the lifeline

Question 18

What does the X mean at the ATM machine lifeline below?

Answer 18

The ATM machine shut down

Question 19

In the ATM example, what is the first action?

Answer 19

insertCard(card_number)

Question 20

In the ATM example, which component validates the card?

Answer 20

The Bank Server (Application)

Question 21

In the ATM example, what happens if the card is invalid?

Answer 21

The machine performs Eject_card(card)

Question 22

In the ATM example, which layer does the ATM Machine belong to?

Answer 22

The Interface (UI) Layer.

Question 23

In the ATM example, which layer does the Database Server belong to?

Answer 23

The Data Layer.

Question 24

What parameter is passed with the ‘requestPIN’ message?

Answer 24

The ‘pin’

Question 25

Which function keyword often leads to a dotted line (Reply for the request)

Answer 25

1. Reply 2. Result (cardValidationResult)

Question 26

What is the return message after 'validateCard'?

Answer 26

cardValidationResult (Valid or Invalid)