Destructor

• Destructor is a special member function of a class, which is used to destroy the object.
• Like a constructor, it has same name as of class name, but it is preceded by tilde (~) sign.
• A destructor has no argument. Also it doesn’t return any value.
• In dynamic constructor ‘new’ is used to allocate the memory.
• Similarly we can use ‘delete’ to free the memory in destructor.
• In short destructor is used to carry out all the clean up activities at the end of program.
• For example we can create the destructor to delete the memory allocated in matrix.

~matrix( )
{
  for(int i = 0 ; i < r; i++)
  {
    delete p[i];
  }
  delete p;
}
 

• The following is an example showing the use of destructor:

/* Program to demonstrate the use of destructor. */

#include "iostream.h"
#include "conio.h"

class destructor
{
   int objno;
   public :   // Constructor to create an object
   destructor()
   {
      cout << "Object is created\n"; 
      cout << "Enter your object number : ";
      cin >> objno;
   }
   // Destructor to destroy an object 
  ~destructor()
   {
     cout << "Object is deleted\n";
     cout << "Object number = " << objno << endl;
   }
};          // Class ends

void main()
{
  clrscr();
  cout << "Main program starts\n";
  destructor d1, d2;
  
  {
    cout << "Inside block-1\n";
    destructor d3;
  }

  {
    cout << "Inside block-2\n";
    destructor d4;
  }
  cout << "Exit main program\n";
  getch();
}