$and operator behavior in MongoDB - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to find documents where age is greater than 25 and status is "A" using $and.

MongoDB

db.collection.find({ $and: [ { age: { $gt: [1] } }, { status: "A" } ] })

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

A25

B30

C20

D15

Attempts:

3 left

💡 Hint

Common Mistakes

Using a value less than 25 will include unwanted documents.

Using a value greater than 25 will exclude some valid documents.

The $gt operator checks if age is greater than 25, so 25 is the correct value to use.

2fill in blank

medium

Complete the code to find documents where score is at least 80 and grade is "B" using $and.

MongoDB

db.collection.find({ $and: [ { score: { $gte: [1] } }, { grade: "B" } ] })

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

A75

B80

C85

D70

Attempts:

3 left

💡 Hint

Common Mistakes

Using a value less than 80 includes lower scores.

Using a value greater than 80 excludes scores exactly 80.

The $gte operator means 'greater than or equal to'. To find scores at least 80, use 80.

3fill in blank

hard

Fix the error in the query to correctly use $and to find documents where city is "NY" and age is less than 30.

MongoDB

db.collection.find({ $and: [ { city: "NY" }, { age: { $lt: [1] } } ] })

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

Aage

B"30"

C30

D25

Attempts:

3 left

💡 Hint

Common Mistakes

Putting 30 in quotes makes it a string, causing no matches.

Using a field name instead of a value causes syntax errors.

The $lt operator expects a number, so 30 without quotes is correct.

4fill in blank

hard

Fill both blanks to find documents where status is "A" and score is greater than 70 using $and.

MongoDB

db.collection.find({ $and: [ { status: [1] }, { score: { $gt: [2] } } ] })

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

A"A"

B70

C75

D"B"

Attempts:

3 left

💡 Hint

Common Mistakes

Using numbers with quotes or strings without quotes.

Mixing up the values for status and score.

Status is a string, so use "A" with quotes. Score is a number, so use 70 without quotes.

5fill in blank

hard

Fill all three blanks to find documents where age is at least 18, city is "LA", and active is true using $and.

MongoDB

db.collection.find({ $and: [ { age: { $gte: [1] } }, { city: [2] }, { active: [3] } ] })

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

A18

B"LA"

Ctrue

Dfalse

Attempts:

3 left

💡 Hint

Common Mistakes

Using strings for numbers or booleans.

Using false instead of true for active.

Age is a number (18), city is a string ("LA"), and active is a boolean (true).