how to Multiple HttpHeader(with same name) in ExpressJS - php

Question

My Php Code can be send two headers with same name, in php second parameter is for replace or override. but in ExpressJS res.header is not like php code
PHP Code:
header("Link: <http://$prefetch_next_img>; rel=prefetch",false);
header("Link: <http://$prefetch_next_img2>; rel=prefetch",false);
http://us2.php.net/manual/en/function.header.php
ExpressJS(NodeJS) :
res.header('Link','Fake Value');
res.header('Link','Only Send it'); // previous header replaced

Answer 1

Ultimately, you'll need to pass an array to set multiple values for the same header
res.header('Set-Cookie', ['foo', 'bar']);
Looking at response library for express we can see the following examples:
/**
* Set header `field` to `val`, or pass
* an object of header fields.
*
* Examples:
*
* res.set('Foo', ['bar', 'baz']);
* res.set('Accept', 'application/json');
* res.set({ Accept: 'text/plain', 'X-API-Key': 'tobi' });
*
* Aliased as `res.header()`.
*
* #param {String|Object} field
* #param {String|Array} val
* #return {ServerResponse} for chaining
* #public
*/
A deeper dive into the code shows us that this is really just a proxy for node's response.setHeader(), which follows the same format
Sets a single header value for implicit headers. If this header
already exists in the to-be-sent headers, its value will be replaced.
Use an array of strings here if you need to send multiple headers with
the same name.
response.setHeader('Set-Cookie', ['type=ninja', 'language=javascript']);