his assignment requires you to construct a class diagram using object-oriented notation. If you are familiar with entity relationship diagrams from previous experience, a class diagram may seem to superficially resemble it, but they are actually quite different. Compare the two diagrams on pages 252 and 257, which are for the same organization, the General Hardware Company, which contrasts an ERD with a class diagram. A key difference is that it is unnecessary to specify the foreign keys in OO diagrams. Another is that the cardinality and modality are expressed differently; inheritance is expressed using arrows, while associations between classes are expressed with connecting lines, but no arrows. Constructing the diagram Most OO diagrams are based on UML, or Unified Modeling Language (Links to an external site.)Links to an external site.. The text does not elaborate much about UML, but it is an extensive topic. Currently, UML 2.2 (Links to an external site.)Links to an external site. has 14 different fundamental types of diagrams divided into two categories, but we will only be concerned with one, the class diagram. The class diagram is particularly useful because it basically shows the database schema for an OO application. You may use any software you wish to construct the diagram, and there are many free UML modeling applications (Links to an external site.)Links to an external site. available, if you are interested. However, even the simple graphics tools available in Microsoft Word are sufficient; even MySQL Workbench, though intended for entity relationship diagrams, can be used. The important thing is to correctly model the relationship between classes, which is going to be either generalization, realization or an association; in addition, all associations have a level of multiplicity that is shown using standard UML notation. Please review the section on Class Level Relationships (Links to an external site.)Links to an external site. in the wikipedia article on UML. For the assignment, you need to diagram the classes, and indicate how they are related. As a hint, the following is a list of all the classes needed: SHIP CRUISE SHIP OIL TANKER CONTAINER SHIP AUTOMOBILE SHIP HULL ENGINE OIL STORAGE TANK You will need to also add the requisite attributes and methods, as described in the case study. Refer to the example diagram on page 261, for the Lucky Rent-A-Vehicle company, to see how attributes and methods are display in a class diagram.