Diagnostic Quiz

Problem

1-2. Sequential Diagrams Loops

The condition can be anything that makes sense to be a terminating or non-terminating condition.

This is the correct way to show a for-loop?

• True

• False

Because the keyword to use is loop, not for.

This question has appeared in CS2113 AY25/26 Sem 1 Final!

1-12. Sequential Diagrams Alternative Paths

There is only alt block in the UML sequential diagrams, there is no if block!

1-14. Sequential Diagrams Calling Convention

The calling convention in UML Sequence Diagrams

• Caller (Sender): The lifeline where the message arrow starts from.

• Receiver: The lifeline where the message arrow points to.

• Method: The label on the arrow (methodName()) is the operation being called on the receiver.

• Parameter: Anything inside the parentheses (param) is data being passed from the caller to the receiver.

• Dashed Lines: It's just at reply message. It can be

  • Return of control

  • Return values

Method m3 calls method m4 of self.

• True

• False

---

Using the convention we have defined at the beginning, we can know that

1. m2(f) is a method from b.

2. m2(f) calls m3() from f and then calls m4() from itself.

Thus, the statement is False because its m2(f), not m3() that calls m4().

1-15. Sequence Diagrams Optional Path

Whatever path/block in the sequence diagram has its scope, the code outside the scope is not controlled by the path/block anymore. It will always be executed.

2-3. Singleton Pattern and Testability

Singleton Pattern can reduce testability?

Tips

1. The condition can be anything that makes sense to be a terminating or non-terminating condition.

2. There is only alt block in the UML sequential diagrams, there is no if block!

3. The calling convention in UML Sequence Diagrams

   • Caller (Sender): The lifeline where the message arrow starts from.

   • Receiver: The lifeline where the message arrow points to.

   • Method: The label on the arrow (methodName()) is the operation being called on the receiver.

   • Parameter: Anything inside the parentheses (param) is data being passed from the caller to the receiver.

   • Dashed Lines: It's just at reply message. It can be

     • Return of control

     • Return values

4. Whatever path/block in the sequence diagram has its scope, the code outside the scope is not controlled by the path/block anymore. It will always be executed.