CSC 1061: Inheritance and Polymorphism Quiz

CSC 1061: Inheritance and Polymorphism

• Course objectives include recognizing when inheritance simplifies related class implementation, implementing derived classes, understanding when abstract base classes facilitate later derived class implementation with shared functions, and understanding the benefits of code reuse.
• The agenda for week 6 features reviewing class relationships ("has a" vs. "is a"), single inheritance, the "why, what, how" of C++ inheritance, demonstration of records as strings, multiple inheritance, and polymorphism.
• Review check involves completing multiple choice questions 1-5, specifically easier multiple-choice questions (10.11.1).
• "Has a" relationships in classes denote a data member relationship (composition), where a class contains an object as a member. For instance, a Player "has a" std::string name.
• "Is a" relationships describe inheritance hierarchies, where a subclass inherits from a superclass. Examples include Shape, Polygon, Rectangle, and Triangle. These relationships are visualized using hierarchical diagrams.
• Single inheritance involves a subclass inheriting properties from a single parent/base class.
• Multiple inheritance involves a subclass inheriting properties from multiple parents/base classes. This is illustrated by diagrams showcasing parent-child relationships, like a child inheriting from two parents in a hierarchical structure.
• Inheritance provides code reuse.
• A publicly derived class inherits all base class members except constructors, destructors, assignment operators, friend functions, and private members. These exceptions are explicitly listed.
• Example inheritance syntax is presented, demonstrating how a Rectangle class can inherit from a Shape base class. Specific examples include Shape, Rectangle, Point, int fillColor, int outline, int fill, int height, int width.
• Inheritance access modes are summarized in a table, detailing which access levels (public, protected, private) are accessible from the class itself, derived classes, and external functions. This table is crucial for understanding access permissions.
• Derived class constructors must call the base class constructor using an initializer list to properly initialize the base class properties. This is a critical step for proper object initialization.
• Records are specialized strings used for structured data storage, such as storing data used in a game, or storing player data. An example player.dat record structure has fields Name and Score. Specific record examples are provided (Record #1, Record #2, Record #3). Record data might include player names and scores.
• Record classes can use std::string non-member functions such as relational operators (==, !=, <, >, <=, >=), operator<<, and string manipulation functions like std::getline, stoi, stod, stof to facilitate efficient data processing and output for records.
• Polymorphism enables a parent class to call a child class's method if the child class overrides the parent's method, and the parent is a pointer to the child object. Both single and multiple inheritance scenarios are applicable for polymorphism. Illustrative code examples demonstrate the call mechanisms between parent and child classes. Pointers are key.
• Rules of inheritance include: parents do not inherently know they have children; parents cannot call child methods; parents cannot be assigned to child objects; children can be used where parents can but not vice versa. Children "are a" type of parent, but parents are not a type of child.