Reading and Writing Files Node

📥 Step 1: Reading a File with `fs.readFileSync()`

Use the fs module (already imported earlier with require('fs')) to read a file:

const fs = require("fs");

const textIn = fs.readFileSync("./txt/input.txt", "utf8");

console.log(textIn);

This function takes two arguments:

📁 File path

./txt/input.txt
The . means the current folder (where index.js lives).
From there, it goes into the txt folder to find input.txt.

🔤 Character encoding

We use 'utf8', which works well for plain text.
Skip this argument, and Node gives you a Buffer (raw data) instead of readable text — not what you want here.

▶️ Run It

In the terminal: node index.js

(Tip: press the ⬆️ Up Arrow to quickly pull up your last command.)

✅ You should see the contents of input.txt printed to the console.

✍️ Step 2: Writing to a File with `fs.writeFileSync()`

📝 Create the Content to Write

Use a template string (ES6 feature) to build the text you want to save:

const textOut=`This is what we know about the avocado:${textIn}. Created on${Date.now()}`;

💾 Write the File

fs.writeFileSync('./txt/output.txt', textOut);
console.log('File written!');

This function takes two arguments:

📁 Path to the file to create/write — ./txt/output.txt
📝 The content to write into that file — the textOut variable

writeFileSync() doesn't return anything meaningful, so there's no need to store its result in a variable.
✅ A console.log() is added afterward just to confirm the file was written successfully.

💻 Full Code:

const fs = require("fs");

const textIn = fs.readFileSync("./txt/input.txt", "utf8");
console.log(textIn);

const textOut = `This is what we know about the avocado:${textIn}. Created on${Date.now()}`;
fs.writeFileSync("./txt/output.txt", textOut);
console.log("File written!");

▶️ Run and Verify

Clear the terminal: Cmd/Ctrl + K or clear
Run the file again:

node index.js

(Or press ⬆️ Up Arrow then Enter.)

📄 A new file called output.txt will appear inside the txt folder.

📄 Opening it will show:
- 📝 The custom text you wrote
- 📖 The original content read from input.txt
- 🕒 The current timestamp (from Date.now())

📥 Step 1: Reading a File with fs.readFileSync()