Revision

Question 1

What is a class diagram?

Answer 1

A static diagram that describes the structure of a system by showing its classes, attributes, operations, and relationships.

Question 2

What is the purpose of a state diagram?

Answer 2

To describe the behavior of a system by showing its states and the transitions between those states.

Question 3

What does a sequence diagram depict?

Answer 3

It shows how objects interact in a particular scenario of a use case, highlighting the sequence of messages exchanged.

Question 4

Define invariant in OCL.

Answer 4

An invariant is a condition that must always hold true for a system at all times.

Question 5

Write an OCL constraint restricting the course name to between 10 and 25 characters.

Answer 5

context Course
inv: courseName.size() >= 10 and courseName.size() <= 25

Question 6

What does the context keyword specify in OCL?

Answer 6

It specifies the class to which the constraint applies.

Question 7

What does the inv keyword declare in OCL?

Answer 7

It declares an invariant constraint.

Question 8

How do you ensure that the length of courseName is at least 10 characters and at most 25 characters in OCL?

Answer 8

courseName.size() >= 10 and courseName.size() <= 25

Question 9

Write an OCL constraint ensuring that if fees are paid, the student must be registered for at least one course.

Answer 9

context Student
inv (feesPaid == True) implies (self.registeredFor->notEmpty())

Question 10

What does the OCL operation ->size() do?

Answer 10

It returns the number of elements in a collection.

Question 11

What does the OCL operation ->isEmpty() check?

Answer 11

It checks if a collection is empty.

Question 12

What does the OCL operation ->notEmpty() check?

Answer 12

It checks if a collection is not empty.

Question 13

What does the OCL operation ->includes(element) check?

Answer 13

It checks if a collection includes a specific element.

Question 14

What does the OCL operation ->forAll(x | condition) do?

Answer 14

It checks if a condition holds true for all elements in a collection.

Question 15

What does the OCL operation ->exists(x | condition) do?

Answer 15

It checks if there exists at least one element in a collection that satisfies a condition.

Question 16

What does the ‘=’ operator represent in OCL?

Answer 16

Equality operator

Question 17

What does the ‘<>’ operator represent in OCL?

Answer 17

Inequality operator

Question 18

What does the ‘and’ operator represent in OCL?

Answer 18

Logical AND operator

Question 19

What does the ‘or’ operator represent in OCL?

Answer 19

Logical OR operator

Question 20

Write an OCL if/else statement ensuring course name size is based on course level.

Answer 20

context Course
inv: if courseLevel = CourseLevel::bachelor then courseName.size() >= 10 else courseLevel = CourseLevel::master and courseName.size() >= 15 endif

Question 21

Write an OCL constraint ensuring student categories and course levels match.

Answer 21

context Student
inv: self.registeredFor-> forAll(course | (studentCategory = StudentCateg::bachelor implies courseLevel = Courselevel::bachelor) and (studentCategory = StudentCateg::master implies courseLevel = Courselevel::master))

Question 22

What is a box-and-line diagram?

Answer 22

A diagram that shows the high-level structure of a system, including its components and the relationships between them.

Question 23

What is a pipe and filter diagram?

Answer 23

A diagram that represents a system as a series of processing steps (filters) connected by pipes, which transport data between the steps.

Question 24

What is the intent of the strategy pattern?

Answer 24

To define a family of algorithms, encapsulate each one, and make them interchangeable, allowing the algorithm to vary independently of clients that use it.

Question 25

What is the applicability of the strategy pattern?

Answer 25

It is applicable when many related classes differ only in their behavior, providing a way to configure a class with one of many behaviors.

Question 26

What does the context class do in the strategy pattern?

Answer 26

It maintains a reference to a strategy object and uses it to execute the algorithm defined by the strategy.

Question 27

What is a concrete strategy in the strategy pattern?

Answer 27

A class that implements a specific algorithm defined by the strategy interface.

Question 28

What is the role of the strategy interface?

Answer 28

To define a common interface for all supported algorithms, allowing them to be interchangeable.