Node.js Fundamentals · Building an API · Lesson 10 of 13
Reading the Request Body
Concept
Reading the Request Body
For POST requests, data arrives in chunks. You collect them and parse the full body once it is done.
By the end of this lesson
- Explain the core idea behind Reading the Request Body.
- Predict output before running a change.
- Test one realistic and one unusual input.
- Use the result to make the next decision.
How to study this page
- 1. Read one concept.
- 2. Change the example.
- 3. Run, compare, and explain.
- 4. Complete the challenge below.
ExampleRunnable
let body = "";
req.on("data", (chunk) => (body += chunk));
req.on("end", () => console.log(JSON.parse(body)));Self-check before continuing
Without looking at the example, describe what changes when you modify one input in Reading the Request Body. Then reopen the editor and prove your explanation with a small test.
You are ready to continue when you can predict, test, and explain the result.
Your turn
Explain why request body data arrives as multiple chunks instead of all at once.
Loading editor…
Console