const fs = require('fs');

// Async
fs.writeFile('example.txt', 'Hello, world!', (err) => {
  if (err) {
    console.error('Error writing file:', err.message);
    return;
  }
  console.log('File written successfully');
});

// Sync
try {
  fs.writeFileSync('example.txt', 'Hello, world!');
  console.log('File written successfully');
} catch (err) {
  console.error('Error writing file:', err.message);
}