What is the destructor and when it’s called?

In C#, a destructor is a special method that is automatically called when an object is being garbage-collected. The destructor is used to perform cleanup tasks and release any unmanaged resources held by the object before it is removed from memory.

The C# destructor is defined using the tilde (~) symbol followed by the class name without any parameters. It is also called the "finalizer." The syntax for a destructor is as follows:

class MyClass
{
    // Constructor
    public MyClass()
    {
        // Constructor logic
    }

    // Destructor (Finalizer)
    ~MyClass()
    {
        // Destructor logic (Cleanup tasks and releasing unmanaged resources)
    }
}

When is the destructor called?
The destructor is called automatically by the .NET garbage collector when the object is no longer referenced or when the garbage collector determines that it is necessary to reclaim memory. The exact timing of when the destructor is called is not guaranteed and is managed by the garbage collector.

It's important to note that in C#, you do not explicitly call the destructor like you would call a regular method. The garbage collector is responsible for invoking the destructor when the object is no longer needed.

While the concept of destructors (finalizers) exists in C#, they are used less frequently in modern C# programming. This is because C# provides better mechanisms for managing resources, such as implementing the IDisposable interface and using the Dispose pattern with the 'using' statement, which allows for more controlled resource cleanup and deterministic disposal of objects. These techniques are preferred over relying solely on destructors for resource management.

Here are some crucial points to remember about destructors:

1. There can only be one destructor in a class.
2. The name of the destructor is the same as the class name, but it is prefixed with a tilde (~) to distinguish it from the constructor.
3. Destructors have no return type and share the same name as the class they are in.
4. Since they are implicitly called by the garbage collector (GC), they do not have any parameters or access modifiers.
5. Destructors cannot be defined in structures; they are exclusively used for classes.
6. Only one destructor is permitted in a class, and therefore, it cannot be overloaded or inherited.
7. It is called when the program terminates its execution or when the garbage collector decides to reclaim the object's memory.
8. Internally, the destructor calls the Finalize() method on the base class of the object.