MongoDB Limit fields and slice projection together?

To limit fields and use slice projection together in MongoDB, use the $slice operator within the projection parameter of the find() method. This allows you to control which fields are returned while simultaneously limiting array elements using slice.

Syntax

db.collection.find(
    { query },
    {
        "field1": 0,
        "field2": 0,
        "arrayField": { "$slice": [startIndex, count] }
    }
);

Sample Data

db.limitAndSliceProjectionDemo.insertOne({
    "_id": 101,
    "UserName": "Carol",
    "UserAge": 26,
    "UserMessage": [
        "Hi",
        "Hello",
        "Bye",
        "Awesome",
        "Good",
        "Bad",
        "Nice",
        "Good Night",
        "Good Morning"
    ]
});

{ "acknowledged": true, "insertedId": 101 }

Example: Limit Fields and Slice Array

Query to exclude specific fields and slice array from index 2 to get 4 elements ?

db.limitAndSliceProjectionDemo.find(
    { "UserName": "Carol" },
    {
        "_id": 0,
        "UserName": 0,
        "UserAge": 0,
        "UserMessage": { "$slice": [2, 4] }
    }
);

{ "UserMessage": [ "Bye", "Awesome", "Good", "Bad" ] }

Key Points

• $slice: [2, 4] starts at index 2 and returns 4 elements.
• Setting field values to 0 excludes them from the result.
• The $slice operator works within the projection stage to limit array elements.

Conclusion

Combine field limiting with $slice projection to control both which fields are returned and how many array elements are included. This provides precise control over query output structure and size.