Program To Demonstrate How Dynamic Objects Can Be Created And Destroyed Using New And Delete Operators Using C++

LEVEL: Beginner

Whats in this post?

  1. Code
  2. Output
  3. Background and Explanation of the code

Code


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Background and Explanation of the code


The above program create and destroy a dynamic object of class rectangle.The statement rectangle *ptr; creates a pointer variable ptr that can point to an object of type rectangle.Initially it contains a garbage value.The statement

ptr = new rectangle;

creates a nameless object of class rectangle at run time, calls the constructor with no parameter and returns the starting address which is stored in pointer variable ptr.The statement

ptr -> read ( );

calls the member function read ( ) of class rectangle through ptr which points to dynamic object.Similarly the next statement;

ptr -> show ( );

displays the data members of dynamic object.

The statement delete ptr ; calls the destructor which destroys the object currently referred by pointer ptr and this memory which gets freed can be reused.Thus , using delete operator, the programmer can destroy the object explicitly anywhere in the program as per the requirement.Hence, the lifetime of the dynamic object can be controlled by the programmer.

OUTPUT

Constructor with no parameter invoked

Enter length and breadth = 4    6

Area of rectangle = 24

Destroying object

Destructor invoked

End of program