$push operator for adding to arrays in MongoDB - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to add a new tag 'urgent' to the tags array in the document.

MongoDB

db.tasks.updateOne({ _id: 1 }, { [1]: { tags: 'urgent' } })

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

A$addToSet

B$push

C$set

D$inc

Attempts:

3 left

💡 Hint

Common Mistakes

Using $set replaces the whole array instead of adding an element.

Using $inc is for numbers, not arrays.

The $push operator adds a value to an array field. Here, it adds 'urgent' to the tags array.

2fill in blank

medium

Complete the code to add the number 5 to the scores array in all documents where the name is 'Alice'.

MongoDB

db.students.updateMany({ name: 'Alice' }, { [1]: { scores: 5 } })

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

A$set

B$inc

C$push

D$pull

Attempts:

3 left

💡 Hint

Common Mistakes

Using $set replaces the whole array.

Using $pull removes elements, not adds.

$push adds the value 5 to the scores array for all matching documents.

3fill in blank

hard

Fix the error in the code to correctly add 'completed' to the status array for the document with _id 10.

MongoDB

db.orders.updateOne({ _id: 10 }, { [1]: { status: 'completed' } })

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

A$set

B$pull

C$addToSet

D$push

Attempts:

3 left

💡 Hint

Common Mistakes

Using $set replaces the entire status field.

Using $pull removes elements instead of adding.

The $push operator correctly adds 'completed' to the status array. Using $set would replace the field.

4fill in blank

hard

Fill both blanks to add multiple tags 'new' and 'sale' to the tags array in one update.

MongoDB

db.products.updateOne({ _id: 5 }, { [1]: { tags: { [2]: ['new', 'sale'] } } })

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

A$push

B$each

C$addToSet

D$set

Attempts:

3 left

💡 Hint

Common Mistakes

Using $set replaces the whole array.

Not using $each adds the array as a single element.

$push adds elements to an array, and $each allows adding multiple values at once.

5fill in blank

hard

Fill both blanks to add the numbers 10, 20, and 30 to the scores array only if they are not already present.

MongoDB

db.players.updateOne({ name: 'Bob' }, { [1]: { scores: { [2]: [10, 20, 30] } } })

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

A$addToSet

B$push

C$each

D$set

Attempts:

3 left

💡 Hint

Common Mistakes

Using $push adds duplicates.

Not using $each adds the array as one element.

$addToSet adds unique values to an array, and $each allows adding multiple values at once.