Destructors

Destructors

A destructor is a special member function that runs when an object is destroyed — when it goes out of scope or is explicitly deleted. Its name is the class name prefixed with ~.

Syntax

class File {
private:
    string name;

public:
    File(string n) {
        name = n;
        cout << "Opened " << name << endl;
    }

    ~File() {
        cout << "Closed " << name << endl;
    }
};

When a File object goes out of scope, the destructor runs automatically:

{
    File f("data.txt");
}  // "Closed data.txt" printed here

RAII — Resource Acquisition Is Initialization

C++ uses the RAII pattern: acquire resources in the constructor, release them in the destructor. This guarantees cleanup even if an exception occurs.

class Connection {
public:
    Connection()  { cout << "Connected" << endl; }
    ~Connection() { cout << "Disconnected" << endl; }
};

Destruction Order

Objects are destroyed in reverse order of their construction:

File a("first");
File b("second");
// destructor order: b, then a

Rules

• A destructor takes no parameters and has no return type
• Each class has exactly one destructor
• If you don't write one, the compiler generates a default that does nothing special
• Always write a destructor if your class manages a resource (memory, file handle, network socket)

Your Task

Create a Logger class that:

• Has a private string name
• Constructor takes a name, stores it, and prints "Logger <name> created"
• Destructor prints "Logger <name> destroyed"
• Has a log(string msg) method that prints "[<name>] <msg>"

Create two loggers, log a message with each, then call their destructors in reverse order.