a learning journal about class diagram.
I found a very useful website on this topic:reference.
Basically, now I know the meaning of different connections:
- solid line with arrow: assosiation, means the static relationship between two classes along with the multiplicity.
- solid line with triangle head: the inheritance feature of the object oriented concept. In Java this can relate to the “extends” keyword.
- dotted line with arrow: Dependency is a relationship that shows that a class is dependent on another class for its existence or implementation.
- dotted line with triangle head: This is related to the relationship between the class and the interface. The realization is equivalent to the “implements” keyword in Java.
- solid line with hollow diamond: This shows “has a” relationship. It is a form of association relationship. This relationship highlights that a whole is made of its parts.So if a whole is destroyed the part still remains.
- solid line with filled diamond: This is again a whole or part relationship where if the whole is destroyed then the part cannot exist independently. Another important point about Composition is that the part at any point in time can have only one owner.