Difference between destructor, dispose and finalize method

Victor Mukherjee picture Victor Mukherjee · Dec 21, 2012 · Viewed 60.7k times · Source

I am studying how garbage collector works in c#. I am confused over the use of Destructor, Dispose and Finalize methods.

As per my research and understandings, having a Destructor method within my class will tell the garbage collector to perform the garbage collection in the way mentioned in the destructor method which cannot be called explicitly on the instances of the class.

The Dispose method is meant to provide the user to control the garbage collection. The Finalize method frees the resources used by the class, but not the object itself.

I am not sure if I understand it the right way. Please clarify the doubts. Any further links or guides are welcome.

Answer

Habib picture Habib · Dec 21, 2012

Destructor implicitly calls the Finalize method, they are technically the same. Dispose is available with objects that implement the IDisposable interface.

You may see : Destructors C# - MSDN

The destructor implicitly calls Finalize on the base class of the object.

Example from the same link:

class Car
{
    ~Car()  // destructor
    {
        // cleanup statements...
    }
}

The Destructor's code is implicitly translated to the following code:

protected override void Finalize()
{
    try
    {
        // Cleanup statements...
    }
    finally
    {
        base.Finalize();
    }
}

Your understanding for the Destructor is right:

From MSDN

The programmer has no control over when the destructor is called because this is determined by the garbage collector. The garbage collector checks for objects that are no longer being used by the application. If it considers an object eligible for destruction, it calls the destructor (if any) and reclaims the memory used to store the object. Destructors are also called when the program exits. It is possible to force garbage collection by calling Collect, but most of the time, this should be avoided because it may create performance issues.