Question

explain the relationship between a deep copy and its pointer.

explain the relationship between a shallow copy and its pointer.

how many bytes are incremented if a pointer such as *p is incremented using pointer arithmetic such as (depending upon which primitive type it point to; int, double, char etc).

write a copy constructor to copy a class object containing a dynamic array. use a member by member copy techniques shown in the textbook.

using correct c++ syntax, write the function defination to overload the operator test for equality: == operator to determine if two objects that have identical components of their dynamic arrays used in above question .

Answer 1

Deep copy and its pointer :

• In deep copy, pointer should point to the different dynamically allocated memory to avoid disasterous consequences.
• So we need to implement user defined copy constructor.

Shallow copy and its pointer :

• In shallow copy, pointer point to the original allocated memory.
• Default copy constructor uses the concept of shallow copy by default.

When we increment pointer by using pointer Arithmetic it uses formula internally how many bytes to increment.

int x=10;

int *p=&x;

p++;   // p=p+1*(sizeof(premitive_datatype)); --> suppose x address is 100 so p contains 100. 100+1*sizeof(int) i.e 4 so p=104 ( 4 bytes are incremented).

Copy Constructur to check identical items in object using overloading of == :

#include<iostream>

using namespace std;
class Demo
{
private:
   int * arr;
   int size;
public:
   Demo(int size)   // Parameterized Constructor
   {
       this->size = size;
       arr = new int[size];
   }
   Demo(const Demo& obj) // User defined Copy constructor
   {
       size = obj.size;
       arr = new int[obj.size];
       for (int i = 0; i<obj.size; i++)
           arr[i] = obj.arr[i];

   }
   void InsertValues() {   // Insert elements into dynamic arrays
       for (int i = 0; i < this->size; i++)
       {
           cin >> arr[i];
       }
       cout << "\n";
          
   }
   void PrintValues()   // Display dynamic array elements.
   {
       for (int i = 0; i < this->size; i++)
       {
           cout <<"\t"<<arr[i];
       }
       cout << "\n";
          
   }
   bool operator ==(Demo obj)   // == Operator overloading to check objects elements.
   {
       for (int i = 0; i < size; i++)
       {
           if (this->arr[i] != obj.arr[i])
               return false;
       }
       return true;
   }
  
};
int main()
{

   Demo obj1(3);            // Object 1
   obj1.InsertValues();   
   obj1.PrintValues();

   Demo obj2 = obj;       // Object 2    --> Here call goes to Copy Constructor
   obj2.PrintValues();

   obj1.InsertValues();   // Insert new elements in Obj1

   if (obj1 == obj2)     // Compare Objects
       cout << "\nBoth are same";
   else
       cout << "\nBoth are different";

   return 0;

}