$unset

db.pets.insertOne(
    {
        pet_name: "coco",
        oops: "get rid of this",
        bad: "dont want this either",
        orthis: true,
    }
);

db.pets.deleteOne({pet_name: "coco"})

---- use above to add/remove the data we'll be playing with---

db.pets.updateOne(
    {pet_name: "coco"},
    {
        $unset: {oops: ""}
    }
)


db.pets.updateOne(
    {pet_name: "coco"},
    {
        $unset: {bad: "", orthis: ""}
    }
)

db.pets.updateOne(
    {pet_name: "coco"},
    [
        {
            $unset: ["oops", "orthis"]
        }
    ]
)