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State Chart diagram

Week 08

objective

• Describe State chart Diagrams in Dynamic Modelling

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Specifying Behaviour

• Interaction diagrams – show how object behave in particular interactions– do not specify all the possible behaviours of objects

• Different notation is needed to summarize the overall behaviour of objects

• UML defines statecharts for this purpose

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The Value of Statechart Diagram • Statechart diagram is the only dynamic

model that can illustrate the milestones in the lifetime of one class of objects in its entirety.

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Ingredients of a State Machine Diagram

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Start State

Stop State

Transition&Self-Transition

Guard Condition/Action

State

Nesting

Decision Point

Notes

[ CorrectDetails ] / acceptPolicy

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State-dependent Behaviour

• Objects respond differently to the same stimulus at different times

• This is modelled by defining a set of states– an object can be in one state at any time– the state it is in determines how it responds to events detected or messages received

– in particular, an event can cause the object to move from one state to another (a transition)

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END