Tutorial 07

Objectives : Learn to create Constructors, Destructors and Creating Dynamic Objects

This week we will implement constructors and destructors. Use your Repl.IT account and use the Instructions provided by your Instructors to complete the Tutorial. All instructions are in the Repl.IT and GitHub Classrooms for the Tutorial Questions for Week 08. Please submit your solutions using Repl.IT itself.

Exercise 1 – Item Class - Constructors and Destructors

a) In the Item.h header file

1. Write the prototype of the default constructor
2. Write the prototype of a overloaded constructor (see main program to identify the parameters)
3. Write the prototype of the destructor

class Item {
   private:
      int itemCode;
      float unitPrice;
      float discount; // out of 100 e.g. discount = 15
   public:
      // 1. Write the Default Constructor
      // 2. Write the Overloaded Constructor
      // 3. Write the Destructor

      void setDiscount(float punitPrice);
      float getDiscount();
      float discountedPrice();
      void display();
};

b) In Item.cpp program

4. Implement the default constructor (initialize all properties to zero)
5. Implement the overloaded constructor
6. Implement the destructor (You should print "Destructor Called")

#include "Item.h"
#include <iostream>
using namespace std;

// 4. Implement Default Constructor Implementation
// 5. Implement Overloaded Constructor Implementation
// 6. Implement Destructor (display "Destructor Called")

void Item::setDiscount(float pdiscount) {
  discount = pdiscount;
}

float Item::getDiscount() {
  return discount;
}

float Item::discountedPrice() {
   return unitPrice - unitPrice * discount/100;
}

void Item::display() {
  cout << "Item : " << itemCode << endl;
  cout << "Discounted Price " << discountedPrice() << endl;
}

Run the program you should get the following output if your program is correct

Item : 0
Discounted Price 0
Item : 100
Discounted Price 800
Destructor Called
Destructor Called

Exercise 2 – Shape Classes - Dynamic Objects

• The Rectangle class is implemented in Rectangle.h and Rectangle.cpp
• The Circle class is implemented in Circle.h and Circle.cpp
• You should not change the code in the Rectangle and Circle classes
• In the Exercise02.cpp program create two dynamic objects as instructed below.

1. Create a dynamic Rectangle type variable (pointer)
2. Create a dynamic Rectangle Object set the length and width that was input from the keyboard
3. Create a dynamic Circle type variable (pointer)
4. Create a dynamic Circle Object set radius that was input from the keyboard
5. Call the display method of the Rectangle Object
6. Call the display method of the Circle Object
7. Delete the Rectangle Object from memory
8. Delete the Circle Object from memory

Do not change any other code in the Exercise02.cpp

#include "Rectangle.h"
#include "Circle.h"
#include <iostream>
using namespace std;

int main() {
  // ========= DO NOT CHANGE THE INPUT CODE BELOW ==================
   int length, width, radius;
   cout << "Enter length of Rectangle : ";
   cin >> length;
   cout << "Enter width of Rectangle : ";
   cin >> width;
   cout << "Enter radius of Circle : ";
   cin >> radius;
   // ======== DO NOT CHANGE THE CODE GIVEN ABOVE ====================
   
   // 1. Create a dynamic Rectangle type variable (pointer)
   // 2. Create a dynamic Rectangle Object set the length and width that was input from the keyboard
   // 3. Create a dynamic Circle type variable (pointer)
   // 4. Create a dynamic Circle Object set radius that was input from the keyboard
   // 5. Call the display method of the Rectangle Object
   // 6. Call the display method of the Circle Object
   // 7. Delete the Rectangle Object from memory
   // 8. Delete the Circle Object from memory
  
  
   // ============ DO NOT CHANGE THE CODE BELOW ===================
   cout << "End of Program" << endl;
  
}