UML Interview Questions

Give a small brief explanation of all Elements in activity diagrams?

Action State	It is a type of state that has an internal action and one outgoing event that would complete the internal action.
State	It is a condition when following events occur:-
Object satisfies a condition.
Or performs a action.
Or wait for a event to happen.
Initial State	It represents a state before any event occurs.
Final State	Represents completion of an activity
Transition Fork	Denotes beginning of parallel path activities.
Transition Join	Denotes merging of parallel path activities.
Control Flow	Represents relationship between two states and actions. In short it indicates that an object in one state is entering some other state.
Object Flow	Connects an object flow state to control flow or action state.
Object in State	Indicate the object’s state after manipulation by multiple activities.
Decisions	Defines if there are any condition’s in the path.
Swim Lanes	Assigns responsibility to action states.
Signal receipt Shape	Used to replace an event label on a transition.
Signal Send Shape	Used to replace an event label on a transition.
Constraint	Conditions that must be maintained true in order the system is valid.
2-Element Constraint	It shows a constraint on two classes or associations.
OR Constraint	It show an OR constraint on two classes or associations.

Explain Different elements of a collaboration diagram?

Classifier Role	It classifies a role.
Association Role	It shows the relation between two classifier roles.
Multi-Object	It used to show operation related to entire set of objects rather than on a single object.
Constraint	Conditions which must be maintained as true in order that system is valid.
2-Element Constraint	It shows a constraint on two classes or associations.
OR Constraint	It shows an OR constraint on two classes or associations.

Explain Component diagrams?

Package	It logically make group of element of a UML model.
Component	It is the actual implementation or physical module of a UML system.
Node	A physical system which represents a processing resource, example PC or a host machine.
Interface	It specifies the externally operations of a class, component, package, or other element without specifying internal structure.
Dependency	Shows relationship between two elements.
2-Element Constraint	It shows a constraint on two classes or associations.
OR Constraint	It shows an OR constraint on two classes or associations.

Explain all parts of a deployment diagram?

Package	It logically groups element of a UML model.
Node	A physical system which represents a processing resource, example PC or a host machine.
Component	It is the actual implementation or physical module of a UML system.
Node instance	It is a runtime physical instance of a processing resource.
Component Instance	It represents an implementation unit that has identity at run time and can contain objects. A component could be contained within a node instance.
Interface	It specifies the external operations of a class, component, package, or other element without specifying internal structure.
Object	Instance of a class.
Composition shape	It is a form of aggregation that indicates that a part may belong to only one element or lifetime of the element.
Communication	How an actor Dependency: - Shows relationship between two elements.
2-Element Constraint	It shows a constraint on two classes or associations.
OR constraint	It shows an OR constraint on two classes or associations.

Describe the various components in sequence diagrams?

Object lifeline	It represents the lifetime of an object creation and its destruction. If the object is created or destroyed during the time the diagram represents, then the lifeline stops or starts at the appropriate point. An object's destruction is marked with a large X.
Activation	It is time during which actor is performing a action.
Lifeline	This says that there exists some condition on the object lifetime.
Message	It shows communication between objects that conveys information and results in an action.
Message (call)	It is same like message but also conveys some information and results in action. All messages have same definition as the Message (Call) given above.
2-Element Constraint	It shows a constraint on two classes or associations.
OR constraint	It shows an OR constraint on two classes or associations.

What are the elements in State Chart diagrams?

State	It is a condition when following events occur:-
Object satisfies a condition.
Or performs a action.
Or waits for an event to happen.	It shows communication between objects that conveys information and results in an action.
Composite State	It has one or more sub states.
Initial State	It represents a state before any event occurs.
Final State	Represents completion of an activity.
Transition	Shows the change of one state to other.
Transition Fork	Denotes beginning of parallel path activities.
Transition Join	Denotes merging of parallel path activities.
Decision	Indicates condition to move to different states.
Shallow History	Represents the state last visited. When a transition to the indicator fires, an object resumes the state, it last had at the same level as the history indicator.
Deep history	A deep history allows you to return from whatever sub-state, Whereas a shallow one only remembers the initial state of a composite state.
2-Element Constraint	It shows a constraint on two classes or associations.
OR constraint	It shows an OR constraint on two classes or associations.