Reading files asynchronously with callbacks in Node.js - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the file system module.

Node.js

const fs = require([1]);

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

A"fs"

B"file"

C"filesystem"

D"path"

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect module names like "file" or "filesystem".

Forgetting the quotes around the module name.

The fs module is imported using require("fs") to access file system functions.

2fill in blank

medium

Complete the code to read a file asynchronously with a callback.

Node.js

fs.readFile('example.txt', 'utf8', [1]);

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

Afunction() { console.log('done'); }

Bconsole.log

C(err, data) => { if (err) throw err; console.log(data); }

D() => console.log('read')

Attempts:

3 left

💡 Hint

Common Mistakes

Passing a callback without parameters.

Not handling the error parameter.

The callback function receives error and data arguments. It handles errors and logs the file content.

3fill in blank

hard

Fix the error in the callback function to properly handle errors.

Node.js

fs.readFile('data.txt', 'utf8', ([1], content) => { if ([1]) throw [1]; console.log(content); });

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

Aerror

Berr

Ce

Dexception

Attempts:

3 left

💡 Hint

Common Mistakes

Using a different variable name in the parameter and in the error check.

Not checking the error parameter at all.

The first parameter in the callback is commonly named err. The code must check err, not error.

4fill in blank

hard

Fill both blanks to read a file and handle errors properly.

Node.js

fs.readFile('log.txt', [1], ([2], data) => { if (err) throw err; console.log(data); });

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

A'utf8'

Berr

Cerror

D'ascii'

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong encoding like 'ascii' when 'utf8' is expected.

Mismatching error parameter name and check.

The encoding should be 'utf8' to read text properly. The error parameter is commonly named err and must match the check.

5fill in blank

hard

Fill all three blanks to read a file asynchronously and log errors or data.

Node.js

fs.readFile([1], [2], ([3], content) => { if (err) console.error(err); else console.log(content); });

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

A'notes.txt'

B'utf8'

Cerr

D'binary'

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong file name or encoding.

Not naming the error parameter correctly.

The file name is 'notes.txt', encoding is 'utf8', and the error parameter is named err to handle errors properly.