Subject: Object Oriented Modeling and Design

Difficulty: Medium

Marks: 8 Marks

Synchronous Messages: A synchronous message is used when sender sends a message to receiver and waits until the receiver processes the sent message. The receiver sends a return message to the sender and then sender continues its processing.It is important when sender needs acknowledgement of sent message from the receiver.It is shown with a directed line from sender to receiver. The line ends at receiver with closed and filled arrow head pointing towards receiver.

Example:-

Asynchronous Messages: An asynchronous message is used when the sender does not wait for the receiver to finish processing the message. A sender continues sending messages to other receiving objects without considering reply from receiver. It is important when sender does not need acknowledgement of sent message from the receiver.It is shown with a directed line from sender to receiver. The line ends with open arrow head pointing towards receiver.

Example:-