Reading and writing buffer data in Node.js - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a Buffer from a string.

Node.js

const buf = Buffer.[1]('Hello');

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

Awrite

Bfrom

Calloc

Dslice

Attempts:

3 left

💡 Hint

Common Mistakes

Using Buffer.alloc() which creates an empty buffer of a fixed size.

Trying to use Buffer.write() which writes data into an existing buffer.

The Buffer.from() method creates a new buffer containing the given string.

2fill in blank

medium

Complete the code to write the string 'Hi' into the buffer at offset 0.

Node.js

buf.[1]('Hi', 0);

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

Awrite

Bfill

Ccopy

Dslice

Attempts:

3 left

💡 Hint

Common Mistakes

Using fill() which fills the buffer with a value but not a string.

Using copy() which copies data between buffers.

The write() method writes a string to the buffer starting at the specified offset.

3fill in blank

hard

Fix the error in reading an unsigned 16-bit integer from the buffer at offset 2.

Node.js

const num = buf.[1](2);

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AreadUInt16BE

BreadInt16LE

CreadUInt8

DreadInt32BE

Attempts:

3 left

💡 Hint

Common Mistakes

Using readUInt8 which reads only 1 byte.

Using readInt32BE which reads 4 bytes instead of 2.

readUInt16BE reads an unsigned 16-bit integer in big-endian format from the buffer at the given offset.

4fill in blank

hard

Fill both blanks to create a buffer of length 5 and fill it with the byte value 0x1F.

Node.js

const buf = Buffer.[1](5);
buf.[2](0x1F);

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

Aalloc

Bfrom

Cfill

Dwrite

Attempts:

3 left

💡 Hint

Common Mistakes

Using Buffer.from() which creates a buffer from data, not size.

Using write() which writes string data, not fills the buffer.

Buffer.alloc(5) creates a buffer of length 5, and fill(0x1F) fills it with the byte value 0x1F.

5fill in blank

hard

Fill all three blanks to create a buffer from a string, write 'OK' at offset 3, and read an unsigned 8-bit integer at offset 4.

Node.js

const buf = Buffer.[1]('Example');
buf.[2]('OK', 3);
const val = buf.[3](4);

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

Afrom

Bwrite

CreadUInt8

Dalloc

Attempts:

3 left

💡 Hint

Common Mistakes

Using Buffer.alloc() instead of Buffer.from() to create buffer from string.

Using readInt8 instead of readUInt8 for unsigned reading.

Buffer.from('Example') creates a buffer from the string. write('OK', 3) writes 'OK' starting at offset 3. readUInt8(4) reads one byte as an unsigned integer at offset 4.