Explain the Memento design pattern.

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Explain the Memento design pattern.

The Memento design pattern is a behavioral design pattern that allows an object to capture and store its internal state so that it can be restored later without violating encapsulation. It involves three main components: the Originator, the Memento, and the Caretaker.

The Originator is the object that has an internal state that needs to be saved and restored. It creates a Memento object that represents the state of the Originator at a particular point in time.

The Memento is an object that stores the state of the Originator. It provides methods to retrieve the saved state and possibly modify it.

The Caretaker is responsible for keeping track of the Mementos and managing their lifecycle. It can request the Originator to save its state by creating a new Memento, or it can request the Originator to restore its state by providing a previously saved Memento.

By using the Memento design pattern, the Originator can save and restore its state without exposing its internal structure to other objects. This pattern is useful in scenarios where you need to implement undo/redo functionality, or when you want to provide a snapshot of an object's state for later use.