Appending to files in Node.js - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to append text to a file using Node.js.

Node.js

import { appendFile } from 'fs/promises';

await appendFile('log.txt', [1]);

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

A'New entry\n'

BreadFile('log.txt')

C'readme.md'

Dconsole.log('append')

Attempts:

3 left

💡 Hint

Common Mistakes

Passing a function call instead of a string as the second argument.

Using the wrong filename or forgetting to add a newline character.

To add text to a file, you use appendFile with the filename and the string to add.

2fill in blank

medium

Complete the code to append 'Hello World' with a newline to 'output.txt'.

Node.js

import { appendFile } from 'fs/promises';

await appendFile('output.txt', [1]);

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

A'Hello World'

B'HelloWorld\n'

C'Hello World\n'

D'Hello\nWorld'

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting the newline character at the end.

Adding newline in the middle of the string.

Appending 'Hello World' with a newline means the string should end with '\n'.

3fill in blank

hard

Fix the error in the code to append text asynchronously.

Node.js

import fs from 'fs';

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

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

A'More data\n'

Bawait 'More data\n'

Cfs.readFile('data.txt')

Dconsole.log('More data')

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'await' inside the callback version of appendFile.

Passing a function or console.log instead of a string.

The appendFile method expects a string as the second argument. Using await here is incorrect because this is a callback style function.

4fill in blank

hard

Fill both blanks to append 'Log entry' with a newline to 'app.log' using promises.

Node.js

import { [1] } from 'fs/promises';

await [2]('app.log', 'Log entry\n');

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

AappendFile

BreadFile

Cappend

DwriteFile

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'writeFile' which overwrites instead of appending.

Using 'readFile' which reads but does not write.

To append text using promises, import and use appendFile from 'fs/promises'.

5fill in blank

hard

Fill all three blanks to append 'Error: ' plus a variable message and newline to 'errors.log'.

Node.js

import { [1] } from 'fs/promises';

const message = 'File not found';
await [2]('errors.log', [3] + message + '\n');

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

AappendFile

BwriteFile

C'Error: '

DreadFile

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'writeFile' which overwrites the file.

Forgetting to add the 'Error: ' prefix string.

Use appendFile to add text. The string to append is 'Error: ' plus the message plus a newline.