Welcome to the final lesson of this course! You've done an outstanding job getting here. Throughout this course, you've deepened your understanding of updateOne and updateMany, and have learned the handy replaceOne method. You’ve also gained hands-on experience with various update operators and learned how to update array elements. In this lesson, we’ll dive deeper into arrays, focusing on how to add and remove items from them. You'll explore the $push, $addToSet, $sort, $pop, $pull, and $pullAll operators. Arrays are a powerful feature in MongoDB, and mastering their manipulation, including techniques for adding single and multiple items, sorting arrays during updates, and maintaining unique entries, will make you a more proficient developer.

Before diving into the specifics of adding and removing elements, let's review the array update operators available in MongoDB:

• $: Updates the first element that matches the query condition.
• : Updates all elements in an array for documents that match the query condition.