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What is fs in JavaScript

The Basics of FS in JavaScript

In the programming world, JavaScript is a popular language known for its versatility in web development. Today, we'll dive into one of its powerful built-in modules called fs, short for 'file system'.

Think of fs as a librarian. Just as a librarian can help you find, read, write, or even delete a book in a library, the fs module can help you perform similar operations but with files on your computer.

Understanding FS

The `fs module in JavaScript provides an API (Application Programming Interface - it's like a menu in a restaurant, listing all the operations you can ask the program to do) to interact with the file system on your computer. This can be incredibly useful if you need to read data from files, write data to files, or modify the contents of files.

How to Use FS

To use the fs module, you first need to require it in your JavaScript file. This is equivalent to calling the librarian and asking for their help. Here's how you do it:

var fs = require('fs');

This line of code is simply asking JavaScript to load the fs library so we can use it in our program.

Reading Files with FS

Now that we've got fs on board, we can ask it to read a file for us. Let's say we have a text file named example.txt. We can read this file using the fs.readFile() function:

fs.readFile('example.txt', 'utf8', function(err, data) {
  if (err) throw err;

Here, we're asking fs to read the file example.txt and give us the data inside it. If there's an error (like if the file doesn't exist), it'll let us know. Once it's done reading, it'll print the data on the console.

Writing Files with FS

Just as we can read files with fs, we can also write files. Let's say we want to create a new file and add some text to it. Here's how we can do it with fs.writeFile() function:

fs.writeFile('newFile.txt', 'Hello World!', function(err) {
  if (err) throw err;
  console.log('File has been saved!');

This code will create a new file called newFile.txt and write 'Hello World!' into it. If there's an error (like if we don't have permission to create a file), it'll let us know.

Deleting Files with FS

Just as a librarian can remove books from the library, fs can also delete files from our system. We can do this using the fs.unlink() function:

fs.unlink('newFile.txt', function(err) {
  if (err) throw err;
  console.log('File has been deleted!');

This will delete the file newFile.txt. If there's an error (like if the file doesn't exist), it'll let us know.


In the grand library of JavaScript, fs is our trusted librarian, equipped with the tools to manage our file system effectively. It may seem daunting at first, but with practice, you'll find it as easy as asking a librarian for a book. So, next time you're working with files in JavaScript, remember, fs is your friend. Don't hesitate to call upon it and use its features to make your programming journey smoother and more efficient. Happy coding!