Node.js Fundamentals · Building an API · Lesson 9 of 13
Sending JSON Responses
Concept
Sending JSON Responses
Set the Content-Type header and use JSON.stringify to send structured data back to the client.
By the end of this lesson
- Explain the core idea behind Sending JSON Responses.
- 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
res.setHeader("Content-Type", "application/json");
res.end(JSON.stringify({ status: "ok" }));Self-check before continuing
Without looking at the example, describe what changes when you modify one input in Sending JSON Responses. 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
Write code that sends { message: "Hello" } as a JSON response.
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Console