$each modifier with $push in MongoDB - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to add multiple items to the array field using $push with $each.

MongoDB

db.collection.updateOne({ _id: 1 }, { $push: { scores: { $each: [1] } } })

Drag options to blanks, or click blank then click option'

A85, 90, 95

B{85, 90, 95}

C(85, 90, 95)

D[85, 90, 95]

Attempts:

3 left

💡 Hint

Common Mistakes

Using curly braces instead of square brackets for the list of values.

Passing values without an array.

The $each modifier requires an array of values to add multiple items to an array field.

2fill in blank

medium

Complete the code to add multiple tags to a document's tags array using $push and $each.

MongoDB

db.collection.updateOne({ name: 'book' }, { $push: { tags: { $each: [1] } } })

Drag options to blanks, or click blank then click option'

A['fiction', 'bestseller']

B{'fiction', 'bestseller'}

C'fiction', 'bestseller'

D(fiction, bestseller)

Attempts:

3 left

💡 Hint

Common Mistakes

Using quotes without brackets, which is not an array.

Using parentheses or curly braces instead of square brackets.

The $each modifier requires an array, so the tags must be inside square brackets.

3fill in blank

hard

Fix the error in the update command to correctly add multiple scores using $push with $each.

MongoDB

db.collection.updateOne({ _id: 2 }, { $push: { scores: { $each: [1] } } })

Drag options to blanks, or click blank then click option'

A{88, 92, 85}

B[88, 92, 85]

C88, 92, 85

D(88, 92, 85)

Attempts:

3 left

💡 Hint

Common Mistakes

Using curly braces or parentheses instead of square brackets.

Passing values without any brackets.

The $each modifier must be followed by an array of values, which uses square brackets.

4fill in blank

hard

Fill both blanks to add multiple new tags and sort them in ascending order.

MongoDB

db.collection.updateOne({ _id: 3 }, { $push: { tags: { $each: [1], $sort: [2] } } })

Drag options to blanks, or click blank then click option'

A['new', 'sale']

B1

C-1

D['old', 'clearance']

Attempts:

3 left

💡 Hint

Common Mistakes

Using a non-array value for $each.

Using -1 for ascending sort instead of 1.

Use an array for $each and 1 for ascending order in $sort.

5fill in blank

hard

Fill all three blanks to add multiple scores, slice the array to keep only the last 3, and sort descending.

MongoDB

db.collection.updateOne({ _id: 4 }, { $push: { scores: { $each: [1], $slice: [2], $sort: [3] } } })

Drag options to blanks, or click blank then click option'

A[70, 75, 80]

B-3

C-1

D3

Attempts:

3 left

💡 Hint

Common Mistakes

Using positive number for $slice to keep first elements instead of last.

Using 1 for $sort when descending order is needed.

$each needs an array, $slice uses negative number to keep last items, and $sort uses -1 for descending order.