What is the notation of an activity parameter?

What is the notation of an activity parameter?

• A. A rectangle that straddles the frame of an activity diagram
• B. A circle at the frame boundary
• C. A dashed line along the frame
• D. A triangle at the corner

Answer: (A)

In UML activity diagrams, an activity parameter is shown as a rectangle that straddles the frame of the activity. This crossing of the boundary visually indicates data that flows between the outside world and the activity itself—values supplied to the activity or produced by it. The portion inside the frame connects to the activity’s internal flow, while the portion outside represents the external input or output. This helps distinguish external data from internal variables, making it clear how information moves across the activity boundary. The other visual options don’t align with this concept: a circle at the boundary isn’t the symbol for an external parameter, a dashed line along the frame isn’t used to denote a parameter, and a triangle at a corner isn’t associated with activity parameters.

In UML activity diagrams, an activity parameter is shown as a rectangle that straddles the frame of the activity. This crossing of the boundary visually indicates data that flows between the outside world and the activity itself—values supplied to the activity or produced by it. The portion inside the frame connects to the activity’s internal flow, while the portion outside represents the external input or output.

This helps distinguish external data from internal variables, making it clear how information moves across the activity boundary. The other visual options don’t align with this concept: a circle at the boundary isn’t the symbol for an external parameter, a dashed line along the frame isn’t used to denote a parameter, and a triangle at a corner isn’t associated with activity parameters.