Q49: How do $slice and$elemMatch function in projection specifiers?
$slice: Limits array items returned in query results (e.g.,{ comments: { $slice: 5 } }returns first 5 comments).$elemMatch(Projection): Limits array output to contain strictly the first array element matching specified criteria.
Key Takeaways
$slicelimits array output lengths or range offsets.$elemMatchprojection returns specific matching array items.
Knowledge Check
Which projection operator limits an array field output to return the LAST 3 items of an array?