Why file system access matters in Node.js - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the Node.js file system module.

Node.js

const fs = require([1]);

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

A"fs"

B"path"

C"http"

D"os"

Attempts:

3 left

💡 Hint

Common Mistakes

Using other module names like "path" or "http" which do not provide file system access.

The fs module is the built-in Node.js module to access the file system. You import it with require("fs").

2fill in blank

medium

Complete the code to read a file asynchronously using the fs module.

Node.js

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

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

Adata

Berr

Cfs

Dconsole

Attempts:

3 left

💡 Hint

Common Mistakes

Logging err instead of data.

Trying to log fs or console which are not file content.

The data parameter contains the file content read by fs.readFile. You log data to see the file content.

3fill in blank

hard

Fix the error in the code to write data to a file asynchronously.

Node.js

fs.writeFile('output.txt', [1], (err) => {
  if (err) throw err;
  console.log('File saved!');
});

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

Aconsole.log

Bfs

Cundefined

Ddata

Attempts:

3 left

💡 Hint

Common Mistakes

Passing fs or console.log instead of the data string.

Passing undefined which causes an error.

The second argument to fs.writeFile must be the data to write. Using data correctly writes the content.

4fill in blank

hard

Fill both blanks to create a directory and then read its contents.

Node.js

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

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

Amkdir

BreadFile

Creaddir

Dunlink

Attempts:

3 left

💡 Hint

Common Mistakes

Using readFile which reads file content, not directory contents.

Using unlink which deletes files.

mkdir creates a directory. readdir reads the contents of a directory. Together they create and list files in 'myFolder'.

5fill in blank

hard

Fill all three blanks to check if a file exists, then read it if it does.

Node.js

fs.[1]('data.txt', (err) => {
  if (!err) {
    fs.[2]('data.txt', 'utf8', (err, [3]) => {
      if (err) throw err;
      console.log([3]);
    });
  } else {
    console.log('File does not exist');
  }
});

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

Aaccess

BreadFile

Cdata

DwriteFile

Attempts:

3 left

💡 Hint

Common Mistakes

Using writeFile instead of readFile to read content.

Not checking if the file exists before reading.

fs.access checks if the file exists. If no error, fs.readFile reads the file. The content is stored in data and logged.