MongoDB C100DBA Exam - Topic 1 Question 48 Discussion

Actual exam question for MongoDB's C100DBA exam

Question #: 48
Topic #: 1

[All C100DBA Questions]

Consider the following document:

> db.c.find()

{ "_id" : 12, b : [ 3, 5, 7, 2, 1, -4, 3, 12 ] }

Which of the following queries on the "c" collection will return only the first five elements of the array in the "b"

field? E.g.,

Document you want returned by your query:

{ "_id" : 12, "b" : [ 3, 5, 7, 2, 1 ] >

Adb.c.find( { > , { b : { $slice : [ 0 , 5 ] } } )

Bdb.c.find( { b : [ 0 , 5 ] > )

Cdb.c.find( { > , { b : { $substr[ 0 , 5 ] > > )

Ddb.c.find( { > , { b : [ 0, 1, 2, 3, 4, 5 ] > )

Edb.c.find( { > , { b : [ 0 , 5 ] > )

Show Suggested Answer

Suggested Answer: A

by Rhea at May 08, 2022, 11:55 PM

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Daron

4 months ago

Definitely A, it's the only one that makes sense here.

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Cordelia

4 months ago

Wait, can you really use $substr on arrays? Sounds off.

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Ilda

4 months ago

Nah, D is totally wrong, it won't work.

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Deeanna

4 months ago

I think B looks right too, but not sure.

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Alva

5 months ago

Option A is the correct syntax for $slice!

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Amina

5 months ago

I'm confused about option C; I don't think $substr works with arrays. It feels like a trick question to me.

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Lashanda

5 months ago

I think I saw a similar question where we had to extract parts of an array, and I remember $slice being the key. So, A seems like the best choice.

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Margart

5 months ago

I'm not entirely sure, but I feel like the syntax in option B looks off. It doesn't seem to use the right format for slicing.

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Alysa

5 months ago

I remember we practiced using the $slice operator to limit array results, so I think option A might be correct.

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Eden

5 months ago

I'm feeling pretty confident about this one. The descriptions seem clear, and I think I can identify the two true statements without too much trouble.

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Tamesha

5 months ago

Okay, let's see. I think the key here is to balance coverage and quality. No critical defects and static analysis showing no major violations seem like good starting points to me.

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