Boolean and null types in MongoDB - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to find documents where the field "active" is true.

MongoDB

db.users.find({"active": [1] })

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

Atrue

Bnull

Cfalse

D"true"

Attempts:

3 left

💡 Hint

Common Mistakes

Using "true" as a string instead of Boolean true.

Using false or null instead of true.

The Boolean value true is used without quotes to query documents where the field is true.

2fill in blank

medium

Complete the code to find documents where the field "deleted" is false.

MongoDB

db.records.find({"deleted": [1] })

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

Anull

Bfalse

C"false"

DTrue

Attempts:

3 left

💡 Hint

Common Mistakes

Using "false" as a string.

Using capitalized False or True.

The Boolean value false is used without quotes to find documents where the field is false.

3fill in blank

hard

Fix the error in the query to find documents where "status" is null.

MongoDB

db.orders.find({"status": [1] })

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

Anull

B"null"

Cundefined

DNone

Attempts:

3 left

💡 Hint

Common Mistakes

Using "null" as a string.

Using undefined or None which cause errors.

Use null without quotes to query documents where the field is null.

4fill in blank

hard

Fill both blanks to find documents where "verified" is true and "deleted" is null.

MongoDB

db.users.find({"verified": [1], "deleted": [2] })

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

Atrue

Bfalse

Cnull

D"true"

Attempts:

3 left

💡 Hint

Common Mistakes

Using "true" or "null" as strings.

Mixing true and false incorrectly.

Use Boolean true for "verified" and null for "deleted" without quotes.

5fill in blank

hard

Fill all three blanks to find documents where "active" is false, "deleted" is null, and "confirmed" is true.

MongoDB

db.accounts.find({"active": [1], "deleted": [2], "confirmed": [3] })

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

Atrue

Bfalse

Cnull

D"false"

Attempts:

3 left

💡 Hint

Common Mistakes

Using quoted strings for Boolean or null.

Mixing true and false values incorrectly.

Use Boolean false for "active", null for "deleted", and Boolean true for "confirmed" without quotes.