$mul operator for multiplication in MongoDB - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to multiply the field 'price' by 2 in the update operation.

MongoDB

db.products.updateOne({ _id: 1 }, { $mul: { price: [1] } })

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

A2

Bprice

C1

D$price

Attempts:

3 left

💡 Hint

Common Mistakes

Using the field name instead of a number as multiplier.

Including a dollar sign before the multiplier number.

The $mul operator multiplies the value of the specified field by the given number. Here, multiplying 'price' by 2 doubles its value.

2fill in blank

medium

Complete the code to multiply the 'quantity' field by 5 for all documents matching the filter.

MongoDB

db.inventory.updateMany({ category: 'books' }, { $mul: { quantity: [1] } })

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

A5

Bcategory

C'5'

D$quantity

Attempts:

3 left

💡 Hint

Common Mistakes

Using a string '5' instead of number 5.

Using the field name or a dollar sign before the multiplier.

The $mul operator requires a number to multiply the field. Here, 5 is the correct multiplier.

3fill in blank

hard

Fix the error in the update command to multiply 'score' by 3.

MongoDB

db.scores.updateOne({ user: 'alice' }, { $mul: { score: [1] } })

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

Ascore

B3

C$3

D'3'

Attempts:

3 left

💡 Hint

Common Mistakes

Using a string '3' instead of number 3.

Using the field name or dollar sign as multiplier.

The multiplier must be a number without quotes or dollar sign. Using 3 correctly multiplies the 'score' field by 3.

4fill in blank

hard

Fill both blanks to multiply 'price' by 1.5 and 'stock' by 10 in a single update.

MongoDB

db.store.updateOne({ _id: 10 }, { $mul: { price: [1], stock: [2] } })

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

A1.5

B10

C'10'

D'1.5'

Attempts:

3 left

💡 Hint

Common Mistakes

Using strings instead of numbers for multipliers.

Mixing up the values for 'price' and 'stock'.

Both multipliers must be numbers without quotes. 1.5 multiplies 'price' and 10 multiplies 'stock'.

5fill in blank

hard

Fill all three blanks to multiply 'rating' by 2, 'views' by 100, and 'likes' by 5 in one update.

MongoDB

db.analytics.updateMany({ active: true }, { $mul: { rating: [1], views: [2], likes: [3] } })

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

A2

B100

C5

D'5'

Attempts:

3 left

💡 Hint

Common Mistakes

Using strings instead of numbers for multipliers.

Using dollar signs or field names instead of numbers.

All multipliers must be numbers without quotes. 2 for 'rating', 100 for 'views', and 5 for 'likes' correctly apply the multiplication.