Consider that our posts collection contains an array field called tags that contains tags that the user enters. { Which of the following commands will find all the posts that have been tagged as tutor

Question

Exhibit

Options

• Adb.posts.find( { tags : ["tutorial"] } );
• Bdb.posts.find( { $array : {tags: "tutorial") > );
• Cdb.posts.find( { tags : "tutorial" } );
• Ddb.posts.findInArray( { tags : "tutorial" > );

• A
  3% (1)
• B
  3% (1)
• C
  95% (37)

Explanation

Option C works because MongoDB automatically searches within array fields when you query with a scalar value - { tags: "tutorial" } matches any document where "tutorial" appears anywhere in the tags array, without needing any special operator.

Why the others fail:

• A uses ["tutorial"] (an array literal), which only matches documents where tags is exactly ["tutorial"] with no other elements - far too restrictive.
• B uses $array, which is not a real MongoDB operator - this will throw an error.
• D uses findInArray(), which is not a real MongoDB method - the driver doesn't expose this function.

Memory tip: In MongoDB, "scalar matches array" - if you query a field with a single value, Mongo is smart enough to check inside arrays for you. You only need array-specific operators ($all, $elemMatch, $size) when your condition is more complex than a simple value match.

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