Creating buffers in Node.js - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a buffer of size 10 bytes.

Node.js

const buf = Buffer.[1](10);

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

Afrom

Bwrite

Calloc

Dslice

Attempts:

3 left

💡 Hint

Common Mistakes

Using Buffer.from instead of Buffer.alloc to create an empty buffer.

Trying to use Buffer.write which is for writing data, not creating buffers.

The Buffer.alloc(size) method creates a new buffer of the specified size filled with zeros.

2fill in blank

medium

Complete the code to create a buffer from the string 'hello'.

Node.js

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

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

Aalloc

Bconcat

Cslice

Dfrom

Attempts:

3 left

💡 Hint

Common Mistakes

Using Buffer.alloc which creates an empty buffer, not from a string.

Using Buffer.slice which extracts part of a buffer, not create one.

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

3fill in blank

hard

Fix the error in the code to create a buffer from an array of bytes.

Node.js

const buf = Buffer.[1]([1, 2, 3, 4]);

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

Afrom

Bwrite

Calloc

Dslice

Attempts:

3 left

💡 Hint

Common Mistakes

Using Buffer.alloc which creates an empty buffer of a given size.

Using Buffer.write which is for writing data into buffers.

To create a buffer from an array of bytes, use Buffer.from(array). Buffer.alloc only allocates empty buffers.

4fill in blank

hard

Fill both blanks to create a buffer of size 5 and fill it with the byte value 255.

Node.js

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

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

Aalloc

Bfrom

C255

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Using Buffer.from instead of Buffer.alloc for allocating empty buffer.

Using 0 as fill value instead of 255.

Buffer.alloc(size, fill) creates a buffer of the given size and fills it with the specified byte value.

5fill in blank

hard

Fill all three blanks to create a buffer from the string 'abc', specify UTF-8 encoding, and slice the first two bytes.

Node.js

const buf = Buffer.[1]('abc', [2]).[3](0, 2);

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

Afrom

B'utf8'

Cslice

Dalloc

Attempts:

3 left

💡 Hint

Common Mistakes

Using Buffer.alloc instead of Buffer.from for string input.

Omitting encoding or using wrong encoding string.

Using wrong method instead of slice to extract bytes.

Buffer.from(string, encoding) creates a buffer from a string with specified encoding. slice(start, end) extracts part of the buffer.