ex02

Exercise 02: Abstract Classes in C++

Core Concepts

1. Abstract Classes

A class with at least one pure virtual function. Cannot be instantiated directly.

class AForm {
    virtual void execute() = 0;  // Pure virtual function
};

2. Pure Virtual Functions

• Declared using = 0 syntax
• Must be implemented by derived classes
• Makes class abstract
• Defines interface for derived classes

3. Virtual Destructor

virtual ~AForm();  // Required for proper cleanup of inheritance hierarchies

4. Class Hierarchy

AForm (Abstract Base)
   ├── ShrubberyCreationForm
   ├── RobotomyRequestForm
   └── PresidentialPardonForm

5. Implementation Requirements

Each concrete form has:

• Specific grade requirements
• Unique execution behavior
• Name and target handling
• Input validation
• Exception handling

6. Key Differences from Base Form

1. ShrubberyCreationForm:

   • Creates ASCII tree file
   • Grades: Sign 145, Execute 137
   • File I/O operations

2. RobotomyRequestForm:

   • 50% success rate
   • Drilling noises
   • Grades: Sign 72, Execute 45

3. PresidentialPardonForm:

   • Simplest execution
   • Highest grade requirements
   • Grades: Sign 25, Execute 5