What is the function of the new field Boolean in the findAndModify() method?

The function of the new field Boolean in the findAndModify() method is to determine whether the updated document or the original document is returned. When this Boolean is set to true, the method returns the modified document after the update has been applied. Conversely, if it is false, it returns the document as it was before the update. This is particularly useful when you need to confirm the results of the modification and can affect the flow of application logic depending on which document version is required after the operation.

Understanding this function helps developers utilize findAndModify() more effectively, allowing them to control the outcome of their read-modify-write cycle in MongoDB.