UML State Diagrams

Communicator
Tools
Profile Settings

Loading, please wait ...

Open its course - Object Oriented Software Engineering

Short Questions for UML State Diagrams

1 Differentiate state dependent objects from state independent objects.

Answer

State Independent Objects
They are modeless and always responds the same way to an event. For example, if an object receives a message, and the responding method always does the same thing. The object is state-independent with respect to that message.
State Dependent Objects
Those object which reacts differently to events depending on their state or mode. For example, a telephone is very state-dependent. The phone's reaction to pushing a particular button (generating an event) depends on the current mode of the phone off hook.
2 Describe the notations available for drawing uml state machine diagram.

Answer
Oval shape represents a state An arrow with a label from one state to another represents a transition A small black circle with arrow into first state represent initial state
3 Draw the state machine for Process Sale use case of the NextGen POS.

Answer
Refer to text book section 29.6.
4 Give examples of some complex reactive objects for which you will have to develop their state diagrams?
Answer

Physical Devices controlled by software e.g. Phone, car, microwave oven.
They have complex and rich reactions to events, and the reaction depends upon their current mode.
Transactions and related Business Objects
How does a business object (a sale, order, payment) react to an event? For example, what should happen to an Order if a cancel event occurs?
Role Mutators
These are objects that change their role. A Person changing roles from being a civilian to a veteran. Each role can be represented by a state.
5 In how many ways the state machines are applied?
Answer
State machines are applied in two ways:
To model the behavior of a complex reactive object in response to events.
To model legal sequences of operations protocol or language specifications. This approach may be considered a specialization of #1, if the "object" is a language, protocol, or process. A formal grammar for a context-free language is a kind of state machine.

Subject Expert

Learn, Evaluate and Optimize

Home

Click to open

Courses

Short Questions for UML State Diagrams

1 Differentiate state dependent objects from state independent objects.

2 Describe the notations available for drawing uml state machine diagram.

3 Draw the state machine for Process Sale use case of the NextGen POS.

4 Give examples of some complex reactive objects for which you will have to develop their state diagrams?

5 In how many ways the state machines are applied?

Subject Expert

Learn, Evaluate and Optimize