destructor

 In C++, a destructor is a special member function of a class that is automatically called when an object goes out of scope or is explicitly deleted using the `delete` operator. The destructor has the same name as the class, preceded by a tilde (`~`). Its primary purpose is to release any resources (such as memory, file handles, network connections, etc.) that the object may have acquired during its lifetime.

Here's a simple example of a class with a destructor:

#include <iostream>

class ResourceHolder {

public:

    // Constructor

    ResourceHolder() {

        std::cout << "Constructor called" << std::endl;

        // Acquire resources or perform initialization here

    }

    // Destructor

    ~ResourceHolder() {

        std::cout << "Destructor called" << std::endl;

        // Release resources or perform cleanup here

    }

};

int main() {

    // Creating an object of class ResourceHolder

    ResourceHolder obj;

    // The object goes out of scope when main() exits

    // The destructor is automatically called at this point

    return 0;

}

In this example:

- When the `ResourceHolder` object is created in the `main` function, the constructor is called.

- When the `main` function exits, and the object `obj` goes out of scope, the destructor is automatically called.

Destructors are particularly useful for managing resources that are not automatically released by the system, such as dynamically allocated memory (`new` and `delete`), file handles, or network connections. It allows you to encapsulate cleanup logic within the class, ensuring that resources are properly released when the object's lifetime ends.

It's worth noting that if you allocate memory with `new` in a class, it is a good practice to release that memory in the class's destructor using `delete`. Alternatively, smart pointers like `std::unique_ptr` or `std::shared_ptr` can be used to automate memory management and eliminate the need for explicit `delete` calls.