Beginner LevelNode JS
How does util.promisify() convert error-first callback functions into Promises?
❓ Interview Prompt: Explain `node:util` module, error-first callback pattern `(err, data) => {}`, and converting functions via `util.promisify()`.
Node.js traditionally used the Error-First Callback pattern '(err, data) => {}'. 'util.promisify()' wraps callback functions to return standard Promises:
Code Implementation Example
javascript
import util from 'node:util';
import child_process from 'node:child_process';
// Convert callback-based exec to Promise-based exec!
const execPromise = util.promisify(child_process.exec);
async function getSystemUptime() {
const { stdout } = await execPromise('uptime');
console.log('System Uptime:', stdout.trim());
}💡Converting callback functions to promises using util.promisify.
🎯 Interview Key Takeaway
Use util.promisify to convert legacy callback functions into clean async/await promises.
#promisify#util#Promises#Callbacks#Beginner
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