What is the notation for a reply message in a sequence diagram?

What is the notation for a reply message in a sequence diagram?

• A. Dashed line with open arrowhead, optional to list
• B. Solid line with a filled arrowhead
• C. Solid line with an open arrowhead
• D. Dashed line with a filled arrowhead

Answer: (A)

In a sequence diagram, a reply message is shown as a dashed line with an open arrowhead. The dashed style signals that this is a return of control rather than a new operation, and the open arrowhead indicates the direction of the return back to the caller. You can optionally annotate the line with the return value or data being sent. The other styles describe different kinds of messages: a solid line with a filled arrowhead is typically a request or call, and a solid line with an open arrowhead is used for other message types in some notations. A dashed line with a filled arrowhead is not used for replies.

In a sequence diagram, a reply message is shown as a dashed line with an open arrowhead. The dashed style signals that this is a return of control rather than a new operation, and the open arrowhead indicates the direction of the return back to the caller. You can optionally annotate the line with the return value or data being sent.

The other styles describe different kinds of messages: a solid line with a filled arrowhead is typically a request or call, and a solid line with an open arrowhead is used for other message types in some notations. A dashed line with a filled arrowhead is not used for replies.