What
does the $count stage return?

Question

What
does the  $count  stage return?

Answer

A
single document that contains the number of fields that have been modified in
an aggregation pipeline.

Answer

A single document with one field that contains
the value set to the number of documents at this stage in the aggregation
pipeline.

Answer

The
number of groups in an aggregation pipeline.

Answer

A
set number of documents from the aggregation pipeline.

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