Reading data with Readable streams in Node.js - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the Readable stream module.

Node.js

const { [1] } = require('stream');

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AReadable

BWritable

CTransform

DDuplex

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing Writable which is for writing data.

Choosing Transform or Duplex which are for other stream types.

The Readable class is imported from the stream module to create readable streams.

2fill in blank

medium

Complete the code to create a readable stream from an array of strings.

Node.js

const readable = Readable.from([1]);

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A['hello', 'world']

B{hello: 'world'}

C'hello world'

D12345

Attempts:

3 left

💡 Hint

Common Mistakes

Passing a single string instead of an array.

Passing an object which is not iterable.

Passing a number which is invalid.

The Readable.from() method creates a readable stream from an iterable like an array of strings.

3fill in blank

hard

Fix the error in the code to read data chunks from the stream.

Node.js

readable.on('data', ([1]) => {
  console.log(chunk.toString());
});

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Abuffer

Bdata

Cchunk

Dstream

Attempts:

3 left

💡 Hint

Common Mistakes

Using a different parameter name than the one used inside the function.

Using a reserved word like 'data' as parameter but not matching usage.

The callback parameter name must match the variable used inside the function. Here, chunk is used to log the data.

4fill in blank

hard

Fill both blanks to correctly handle the end of the readable stream.

Node.js

readable.on('[1]', () => {
  console.log('[2]');
});

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Aend

Bfinish

Cclose

Dend of stream reached

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'finish' which is for writable streams.

Using 'data' which is for data chunks.

Using 'close' which is different and less common here.

The end event signals that no more data will be provided by the stream. Logging a message inside this event handler informs the user.

5fill in blank

hard

Fill all three blanks to create a readable stream and log all data chunks and the end event.

Node.js

const { [1] } = require('stream');

const data = ['Node', 'JS', 'Streams'];
const readable = [2].from(data);

readable.on('data', ([3]) => {
  console.log([3].toString());
});

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

AReadable

Cchunk

Dbuffer

Attempts:

3 left

💡 Hint

Common Mistakes

Using different names for import and usage.

Using wrong parameter names in the event handler.

Not calling from() on the Readable class.

First, import Readable. Then create a readable stream from the array data using Readable.from(). Finally, listen to the 'data' event with a parameter chunk to log each data piece.