Lab 4

The purpose of this lab is to practice inheritance and invoking base constructors with arguments. For this lab you will define a base class and three derived classes that will inherit all members with public inheritance. For each class definition, you will write a default constructor and constructor with argument(s). For each derived class constructor definition, you will invoke the base's corresponding constructor. The class definitions, constructors, and member functions you will write are as follows:

Base Class - Shape

This class will contain one protected staticallly sized cstring member variable called 'identity'. Within the public section, this class will contain only a constructor that will accept a constant cstring as an argument, an inputShape and a printShape member function.

• Shape(const char* id) - constructor w/ const cstring argument: assign the passed argument to the 'identity' member variable.
• void inputShape() - empty definition {} (**NOTE** in the future we will learn a topic of pure virtual functions and abstract base classes; topics related to 'polymorphism')
• void printShape() - output the 'identity' member variable.

Derived Class - Rectangle

This class will inherit members of the Shape class. In addition, this class will contain two protected member variables 'length' and 'width'.

• Rectangle() - default constructor: this will invoke the Shape constructor and pass string literal "Rectangle", and zero 'length' and 'width'.
• Rectangle(const int l, const int w) - constructor w/ two const integer arguments: invoke the Shape constructor passing string literal "Rectangle" as an argument, then set the passed integer values to members length and width.
• void inputShape() - redefine the Shape function and prompt the user for two positive integer values and set the length and width accordingly.
• void printShape() - redifine the Shape function and call the Shape's printShape function. Then output the length and width member variables. Then call the getArea() function that will return the area of the rectangle
• int getArea() - This function will return the area of the object (length * width).

Derived Class - Triangle

This class will inherit members of the Shape class. In addition, this class will contain two protected member variables 'base' and 'height'.

• Triangle() - default constructor: this will invoke the Shape constructor and pass string literal "Triangle", and zero 'base' and 'height'.
• Triangle(const int l, const int w) - constructor w/ two const integer arguments: invoke the Shape constructor passing string literal "Triangle" as an argument, then set the passed integer values to members base and height.
• void inputShape() - redefine the Shape function and prompt the user for two positive integer values and set the base and height accordingly.
• void printShape() - redefine the Shape function and call the Shape's printShape function. Then output the base and height member variables. Then call the getArea() function that will return the area value of the triangle.
• float getArea() - This function will return the area of the object ((1/2) * base * height).

Derived Class - Circle

This class will inherit members of the Shape class. In addition, this class will contain one protected member variable 'radius'.

• Circle() - default constructor: this will invoke the Shape constructor and pass string literal "Circle", and zero 'radius'.
• Circle(const int r) - constructor w/ const integer argument: invoke the Shape constructor passing string literal "Circle" as an argument, then set the passed integer value to member radius.
• void inputShape() - redefine the Shape function and prompt the user for a positive integer value and set the radius accordingly.
• void printShape() - redefine the Shape function and call the Shape's printShape function. Then output the radius member variable. Then call the getArea() function that will return the area value of the circle.
• float getArea() - This function will return the area of the object (3.14159 * r * r).

Lab4 Main

A partial version of main has been given to you with an example derived class called 'Square'. Fill in the missing cases within the switch and instantiate a Rectangle, Triangle, and Circle object within the doWhile loop.