estimatedDocumentCount for speed in MongoDB - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to get the estimated number of documents in the collection.

MongoDB

const count = await collection.[1]();

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

AestimatedDocumentCount

BcountDocuments

Cfind

Daggregate

Attempts:

3 left

💡 Hint

Common Mistakes

Using countDocuments() which is slower because it scans documents.

Using find() which returns documents, not a count.

Using aggregate() which is for complex queries.

The estimatedDocumentCount() method quickly returns an estimate of the total number of documents in a collection without scanning the entire collection.

2fill in blank

medium

Complete the code to print the estimated document count from the collection.

MongoDB

collection.[1]().then(count => console.log(count));

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AcountDocuments

Bfind

CestimatedDocumentCount

DdeleteMany

Attempts:

3 left

💡 Hint

Common Mistakes

Using deleteMany() which deletes documents instead of counting.

Using find() which returns documents, not a count.

Using countDocuments() which is slower.

estimatedDocumentCount() returns a promise that resolves to the estimated number of documents, which we print.

3fill in blank

hard

Fix the error in the code to get the estimated document count correctly.

MongoDB

const count = await collection.[1];

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

AestimatedDocumentCount

BestimatedDocumentCount()

CcountDocuments()

DcountDocuments

Attempts:

3 left

💡 Hint

Common Mistakes

Omitting parentheses after the method name.

Using countDocuments() which is slower.

Using property without calling it as a function.

The method estimatedDocumentCount() must be called with parentheses to execute and return a promise.

4fill in blank

hard

Fill both blanks to estimate the document count and handle errors.

MongoDB

collection.[1]().catch(error => console.[2](error));

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AestimatedDocumentCount

Berror

Cerror.log

Dconsole.error

Attempts:

3 left

💡 Hint

Common Mistakes

Using console.log instead of console.error for errors.

Using countDocuments instead of estimatedDocumentCount.

Using error.log which is not a function.

Use estimatedDocumentCount() to get the count and console.error to print errors.

5fill in blank

hard

Fill all three blanks to estimate document count, assign it to a variable, and print it.

MongoDB

async function getCount() {
  const count = await collection.[1]();
  console.[2]('Estimated count:', [3]);
}

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

AestimatedDocumentCount

Blog

Ccount

DcountDocuments

Attempts:

3 left

💡 Hint

Common Mistakes

Using countDocuments instead of estimatedDocumentCount.

Using console.error instead of console.log for printing count.

Printing the method name instead of the variable.

Call estimatedDocumentCount() to get the count, then use console.log to print the variable count.