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Dissection of Modeling Attribute

Modeling attributes
Modeling attributes

Modeling attribute dissection involves examining all of the elements
  1. Derived attribute indicator: Optional
  2. Attribute name: Required
  3. Data type: Required
  4. Assignment operator and default value: Optional
  5. Constraints: Optional
  6. Visibility: Required before code generation
  7. Class attribute: Optional

Attribute Modeling

System of Objects

Objects do not exist in isolation, but as part of a larger system of objects that must interact with each other. The most fundamental relationship between objects is the has a relationship. The Java implementation of the Book class has three String attributes: title, author, and ISBN. String is a class, and the relationship between the Book class and the String class is illustrated in Figure 4-3.

The has a relationship
Figure 4-3: The 'has a' relationship
The preceding figure is an example of a Booch class diagram. Grady Booch developed this notation for representing the relationships between the classes that comprise a software system. The simplest relationship is the has a relationship. The filled-in circle at one end of the connecting line indicates that it is the Book that has the String.