MongoDB - Query on the last element of an array?

Question

I know that MongoDB supports the syntax find{array.0.field:"value"}, but I specifically want to do this for the last element in the array, which means I don't know the index. Is there some kind of operator for this, or am I out of luck?

EDIT: To clarify, I want find() to only return documents where a field in the last element of an array matches a specific value.

Answer 1

In 3.2 this is possible. First project so that myField contains only the last element, and then match on myField.

db.collection.aggregate([
   { $project: { id: 1, myField: { $slice: [ "$myField", -1 ] } } },
   { $match: { myField: "myValue" } }
]);