go-patterns/behavioral/memento.md

The Memento pattern allows the state of an object to be saved and restored. It helps us write undo-redo operations through the use of the three componants:

• Originator: It is the actual object whose state is saved as a memento.
• Memento: This is the object which saves the state of the originator
• Caretaker: This is the object that saves multiple mementos. Given an index, it returns the corresponding memento.

The originator defines two methods. savememento() and restorememento()

• savememento()- in this method the originator saves its internal state into a memento object.
• restorememento()- this method takes input as a memento object. The originator restores itself to the pass memento. Hence a previous state is restored.