Communication Diagram

  • How objects associate with each other
  • Focus on links, rather than the order
  • Give big overview of interaction between objects in the system
  • Easy to draw
Nested message
  • A message that is invoked because of another message
  • Use number scheme for such nested message e.g. 1.1 MessageX()
Concurrent message

2 ways

  1. using number and letter notation
  2. using open arrowhead
Conditional messages
  • messages that are sent based on condition
  • represented as guard
  • usually made up boolean statement, represented as pseudocode
Looping message
  • showed as asterisk before looping constraints
  • represented like a guard statement
  • may contain a condition with boolean statement or counter variable
Message to self
Create message
  • creates an instance of a class
  • Message name is Create with arguments as the name of the class
  • Use the stereotype <<create>> on the message name of any name
Destroy message
  • Destroy an instance of a class
  • Use stereotype <<destroy>> on the name of the message
  • In C++, the delete operator can be used