CS2113/T Website - UML: Class Diagrams: Associations: Navigability

You should use arrow heads to indicate the navigability of an association.

Logic is aware of Minefield, but Minefield is not aware of Logic

class Logic{
    Minefield minefield;
}

class Minefield{
    ...
}

class Logic:
  
  def __init__(self, minefield):
    self.minefield = minefield
    
  # ...


class Minefield:
  # ...

Here is an example of a bidirectional navigability; each class is aware of the other.

Navigability can be shown in class diagrams as well as object diagrams.

According to this object diagram the given Logic object is associated with and aware of two MineField objects.

a. A Unit object knows about the Item object it is linked to
b. An Item object knows about the Unit object it is linked to
c. Depends on the programming language

(a)

Explanation: The diagram indicates that Unit object should know about the Item object. In the implementation, the Unit object will hold an Item object in one of its variables.