Object-Oriented Design Steps Quiz

Object-Oriented Design Steps

• Object-oriented design identifies classes, methods, and messages needed for a use case.
• Design is carried out for each use case individually.

Design Class Diagrams

• Stereotype: Categorizes model elements by characteristics (e.g., <<>>).
• Persistent Class: Objects persist after system shutdown (data remembered).
• Entity Class: Identifies domain problem classes (usually persistent).
• Boundary Class/View Class: Exists on system boundaries (e.g., input windows, web pages).
• Controller Class: Mediates between boundary and entity classes, acting as a switchboard between view and domain layers.
• Data Access Class: Retrieves and sends data to/from database.

Notation for Design Class Syntax

• Attributes:

  • Visibility: Indicates access (+ public, - private).
  • Name: Lower camel case (e.g., attributeName).
  • Type: Data type (e.g., string, integer, date).
  • Initial Value (if applicable): Default value.
  • Property (if applicable): Indicates a key (e.g., {key}).

• Methods:

  • Visibility: Indicates access (+ public, - private).
  • Name: Lower camel case (e.g., methodName).
  • Parameters: Variables passed to a method.
  • Return Type: Data type returned by the method.

• Examples:

  • accountNo: String {key}
  • startingJobCode: integer = 01
  • +getName(): string
  • -checkValidity(date): int

• Class Level Methods (Static Methods): Methods that apply to the class itself, not individual objects, underlined (e.g., _findStudentsAboveHours(hours): Array).

• Class Level Attributes (Static Attributes): Attributes belonging to the class, not individual objects, underlined (e.g., _noOfPhoneSales: int).

• Abstract Classes: Cannot be instantiated; used for inheritance (italicized).

• Concrete Classes: Can be instantiated.