UML Sequence Diagrams Quiz

What is the purpose of gates in UML sequence diagrams?

• To specify the concrete sender and receiver for every message

• To represent the duration of an execution

• To show a runtime constraint on the participants of the interaction

• To allow the use of another interaction

What does a lifeline represent in a UML sequence diagram?

• An individual participant in the interaction

• A moment in time at the beginning or end of a message

• A named element representing the most general interaction unit

• A period in the participant's lifetime when it is executing a unit of behavior

What does an occurrence specification represent in UML sequence diagrams?

• An occurrence which represents sending and receiving of signals or invoking or receiving of operation calls

• An interaction fragment which represents a runtime constraint on the participants of the interaction

• A message occurrence which represents the destruction of the instance described by the lifeline

• A moment in time at the beginning or end of a message or at the beginning or end of an execution

What is the purpose of an interaction use in UML sequence diagrams?

• To specify a runtime constraint on the participants of the interaction

• To represent the duration of an execution

• To relate a message outside of an interaction fragment with a message inside the interaction fragment

• To use (or call) another interaction and simplify large and complex sequence diagrams

How is a state invariant represented in a UML sequence diagram?

• As a wider labeled rectangle representing the execution specification

• As a thin grey or white rectangle on the lifeline

• As a combined fragment with operator ref

• As a constraint in curly braces on the lifeline