This one is Todo.remove, and Todo.remove works kind of like Todo.find. You pass in a query and that query matches multiple records, removing all of them. If it matches none, none will get removed. Now, the difference between Todo.find and Todo.remove, other than the fact that remove removes the docs, is that you can't pass in an empty argument and expect all the documents to get removed. If you want to remove everything from your collection you need to run it like Todo.remove({}). If we run this we're going to have everything get removed. I'm going to tack then. We're going to get back our result and we can print that result to the screen using console.log(result), just like this:

Todo.remove({}).then((result) => { 
   console.log(result); 
});

Now we can run the mongoose-remove file, which is going to remove all of the Todos from our database:

node playground/mongoose-remove.js

Now when we run the remove method, once again we get back a result object; a lot of this stuff is not useful to us but up at the very top there is a result property. We can see that the removal did work, we got a 1 back as opposed to 0, and we have the number of records that were removed. In this case the number of records happens to be 3.