Regex queries in MongoDB - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to find documents where the 'name' field starts with 'A'.

MongoDB

db.collection.find({ name: { $regex: /^[1]/ } })

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

AA

Ba

C^A

D.*A

Attempts:

3 left

💡 Hint

Common Mistakes

Including the caret (^) inside the blank causes a syntax error.

Using lowercase 'a' will not match uppercase 'A'.

The regex /^A/ matches strings starting with 'A'. Here, the caret (^) is outside the blank, so only 'A' is needed.

2fill in blank

medium

Complete the code to find documents where the 'email' field contains 'gmail'.

MongoDB

db.collection.find({ email: { $regex: /[1]/ } })

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

Agmail

Bgmail$

C^gmail

D^gmail$

Attempts:

3 left

💡 Hint

Common Mistakes

Using '^gmail' matches only strings starting with 'gmail'.

Using 'gmail$' matches only strings ending with 'gmail'.

The regex /gmail/ matches any string containing 'gmail' anywhere.

3fill in blank

hard

Fix the error in the code to find documents where 'username' ends with '123'.

MongoDB

db.collection.find({ username: { $regex: /[1]$/ } })

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

A.*123

B^123

C123$

D123

Attempts:

3 left

💡 Hint

Common Mistakes

Including '$' inside the blank causes a syntax error.

Using '^123' matches start of string, not end.

The dollar sign ($) is already outside the blank, so inside the blank we only put '123'.

4fill in blank

hard

Fill both blanks to find documents where 'title' contains 'data' ignoring case.

MongoDB

db.collection.find({ title: { $regex: /[1]/, $options: '[2]' } })

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

Adata

Bi

Cg

D^data

Attempts:

3 left

💡 Hint

Common Mistakes

Using '^data' matches only start of string.

Using 'g' option is for global search, not needed here.

The regex /data/ matches 'data' anywhere. The option 'i' makes the search case-insensitive.

5fill in blank

hard

Fill all three blanks to find documents where 'description' starts with 'Error' and ends with a digit.

MongoDB

db.collection.find({ description: { $regex: /^[1].*[2]$/, $options: '[3]' } })

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

AError

B\d

Ci

Dg

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting to escape the backslash in '\d'.

Using 'g' option which is not needed for find queries.

The regex /^Error.*\d$/ matches strings starting with 'Error' and ending with a digit. The 'i' option ignores case.