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Destructors in C++

A destructor in C++ is a special member function of a class that is executed when an object of that class is destroyed. The destructor is used to clean up resources that the object may have acquired during its lifetime, such as dynamically allocated memory or file handles.

Key Points About Destructors

• The destructor has the same name as the class but is preceded by a tilde (~) symbol.
• It does not take any arguments and does not return any value.
• Destructors are automatically called when an object goes out of scope or is explicitly deleted.
• Each class can have only one destructor.

Example of a Destructor

Here’s an example demonstrating the use of a destructor to clean up dynamically allocated memory:

#include <iostream>

class MyClass {
public:
    int* data;
    // Constructor
    MyClass(int size) {
        data = new int[size]; // Allocate memory dynamically
        std::cout << "Constructor Called" << std::endl;
    }
    // Destructor
    ~MyClass() {
        delete[] data; // Deallocate memory
        std::cout << "Destructor Called" << std::endl;
    }
};

int main() {
    MyClass obj(5); // Calls constructor
    // When obj goes out of scope, destructor is called
    return 0;
}
                    

In this example, the constructor MyClass(int size) allocates memory for an array of integers. The destructor ~MyClass() is responsible for deallocating this memory when the object obj goes out of scope. This ensures that there are no memory leaks.

Important Points:

• Destructors help manage resource cleanup and prevent memory leaks.
• They are called automatically when an object is destroyed, so you don’t need to manually invoke them.
• Destructors should be used to release any resources acquired by the object, such as dynamically allocated memory or file handles.