Explain Polymorphism, Iterated Messages and use of self in message in collaboration diagram.

Polymorphism, iterated messages, and the use of self in messages are concepts often used in collaboration diagrams within the Unified Modeling Language (UML) to represent interactions between objects in a system. Let’s delve into each of these concepts:

Polymorphism:

1. Definition: Polymorphism means having many forms.
2. Explanation: In the context of object-oriented programming, polymorphism refers to the ability of objects of different classes to be treated as objects of a common base class. It allows a message to be displayed in more than one form based on the type of object it is invoked upon.
3. Role in Collaboration Diagrams: Polymorphism plays a crucial role in collaboration diagrams by enabling objects with different internal structures to share the same external interface. This simplifies the representation of interactions, making it more abstract and generic.

Iterated Messages:

1. Definition: Collaboration diagrams use syntax similar to sequence diagrams to indicate that a message iterates (is run multiple times) or is run conditionally.
2. Explanation: Messages can be marked as iterated by using an asterisk (*) or a specific number to indicate the number of times a message is repeated. Conditional iterations can be represented by adding a conditional clause.
3. Role in Collaboration Diagrams: Iterated messages help capture the repetitive or conditional nature of certain interactions between objects. They enhance the expressiveness of collaboration diagrams by representing scenarios where a message is not executed just once.

Use of Self in Message:

1. Definition: Self represents the ability of an object to send a message to itself.
2. Explanation: In the context of collaboration diagrams, the term “self” is used to show that an object is invoking a message on itself. This is often represented by a loop arrow from the object back to itself.
3. Role in Collaboration Diagrams: The use of self in messages allows the modeling of scenarios where an object triggers an action within itself. It is particularly useful in illustrating recursive or self-invoking behavior within the system.