Difference between Finalize() and Dispose()

In .NET, the Finalize() and Dispose() methods are used for releasing unmanaged resources, such as file handles, database connections, or network connections, in order to ensure proper cleanup and prevent resource leaks. While both methods serve a similar purpose, there are significant differences in their implementation and usage.


The Finalize() method is a protected method defined in the System.Object class. It is part of the garbage collection mechanism and is automatically called by the garbage collector when an object is being reclaimed. The Finalize() method is responsible for performing cleanup operations on unmanaged resources before the object is destroyed. It is called during the finalization phase of the garbage collection process.

Here's an example of using the Finalize() method:

public class MyClass { // Finalizer ~MyClass() { // Cleanup unmanaged resources } }

The Finalize() method is non-deterministic, meaning it is not guaranteed to be called immediately when the object is no longer referenced. Instead, it is called at some point in the future by the garbage collector. This makes it less predictable and may result in delayed cleanup of resources.


The Dispose() method is part of the IDisposable interface, which is used for explicit resource cleanup. It provides a deterministic way to release unmanaged resources before the object goes out of scope. Unlike Finalize(), Dispose() can be explicitly called by the developer to release resources immediately.

public class MyClass : IDisposable { // IDisposable implementation public void Dispose() { // Cleanup unmanaged resources } }

The Dispose() method should be called explicitly when the object is no longer needed, typically using the using statement or by calling Dispose() directly. This ensures timely release of resources and allows for more efficient resource management.

To summarize the differences:
  1. Finalize() is automatically called by the garbage collector, while Dispose() is called explicitly by the developer.
  2. Finalize() is non-deterministic and may introduce delays in resource cleanup, whereas Dispose() provides deterministic cleanup.
  3. Finalize() is used for cleaning up unmanaged resources, while Dispose() can be used for both unmanaged and managed resources.
  4. Finalize() is defined in the base Object class, while Dispose() is part of the IDisposable interface.


It's worth noting that it is common practice to implement both Finalize() and Dispose() methods in a class. The Finalize() method acts as a fallback in case Dispose() is not explicitly called, ensuring that unmanaged resources are eventually released. However, it is recommended to call Dispose() explicitly when possible to ensure timely cleanup and efficient resource management.