Promise in Node

Promises in Node.js work the same as in JavaScript, but understanding how they integrate with Node.js's async nature is important.

Key Concepts

• Handle asynchronous operations
• Better than callbacks
• Chain operations easily
• Error handling with catch

---

Example 1

then((result) => { console.

log(result); return p2; console.

catch((err) => console.

log(err)); Promise.

all([p1, p2]).

catch((error) => console.

log(error)); Promise.

allSettled([p1, p2]).

then((result) => {.

Code

const p1 = new Promise((resolve, reject) => {
  setTimeout(() => resolve(1), 1000);
});
const p2 = new Promise((resolve, reject) => {
  setTimeout(() => reject(new Error("P2 failed")), 5000);
});

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Summary

Understanding promise is essential for mastering node. Practice these examples and experiment with variations to deepen your understanding.

Key Takeaways

• promise is a fundamental concept in node
• Practice with these examples to build confidence
• Experiment with variations to explore edge cases
• Understanding promise will help you in technical interviews