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Element: Choice

A choice is a node in a statechart. The subsequent guard conditions are evaluated at the node within a cycle. It has at least one incoming transition and one outgoing transition. Choice nodes can be located in a statechart at the top position, in composite states, or in regions of orthogonal states. When multiple choice nodes are linked by transitions, no circular link may be created, such as a trace back to a choice that is already a source element for a transition within this chain.

_uml_img_choice.png

The circle with the flow control number provides information about the order of processing.

Properties

Property

Description

Identifier

Unique name for the selected element. It is not displayed in the statechart.

User input

Action

Description

  1. Select a Choice element.

    _uml_img_choice_selected.png

  2. 2. Click the _uml_icon_transition_outgoing.png symbol.

  3. 3. Click an existing element (type: State, Composite state, Fork/Join, or Choice).

A transition is inserted between the two elements.

Example

Example 28. Statechart with choice
_uml_img_example_choice.png