how to append response header in node

To append a response header in Node.js, you can use the setHeader method of the response object. Here are the steps to do it:

1. Access the response object: In your Node.js application, you will have a callback function that handles the HTTP request and response. Inside this function, you can access the response object.

2. Use the setHeader method: Call the setHeader method on the response object to set the desired header. The method takes two arguments: the header name and the header value.

3. Example code: Here's an example that demonstrates how to append a response header in Node.js:

const http = require('http');

const server = http.createServer((req, res) => {
  res.setHeader('Content-Type', 'text/plain');
  res.setHeader('X-Custom-Header', 'Custom Value');
  res.end('Hello, world!');
});

server.listen(3000, () => {
  console.log('Server is running on port 3000');
});

In this example, we set the Content-Type header to text/plain and the X-Custom-Header to Custom Value. You can modify these values according to your requirements.

That's it! The response header will be appended to the HTTP response and sent back to the client.