File Operations in Node.js
From the Node.js Core Modules cheat sheet · File System (fs) · verified Jul 2026
File Operations
Read, write, delete files with async and sync methods
javascript
// Read file
const data = fs.readFileSync('file.txt', 'utf8');
fs.readFile('file.txt', 'utf8', (err, data) => {});
// Write file
fs.writeFileSync('file.txt', 'content');
fs.appendFileSync('file.txt', 'more');
// Delete/Check
fs.unlinkSync('file.txt');
fs.existsSync('file.txt');🟢 Essential - Every Node.js app deals with files
💡 Use async methods (fs.promises) to avoid blocking
⚠️ Always handle errors in file operations
📌 Use path.join() for cross-platform paths
⚡ Stream large files instead of reading all at once
🔗 Related: fs-extra for additional utilities