What is the difference between res.send and res.write in express?

Question

I am a beginner to express.js and I am trying to understand the difference between res.send and res.write ?

Answer 1

res.send

• res.send is only in Express.js.
• Performs many useful tasks for simple non-streaming responses.
• Ability to automatically assigns the Content-Length HTTP response header field.
• Ability to provides automatic HEAD & HTTP cache freshness support.
• Practical explanation
  • res.send can only be called once, since it is equivalent to res.write + res.end()
  • Example:

    app.get('/user/:id', function (req, res) {
        res.send('OK');
    });
    

For more details:

• Express.js: Response

---

res.write

• Can be called multiple times to provide successive parts of the body.
• Example:

  response.write('');
  response.write('');
  response.write('
  Hello, World!
  ');
  response.write('');
  response.write('');
  response.end();
  

For more details:

• response.write(chunk[, encoding][, callback])
• Anatomy of an HTTP Transaction: Sending Response Body