What are cache headers in Express.js and how do I use them?

What are cache headers in Express.js and how do I use them?

Cache headers are HTTP headers that control how responses are cached by browsers and intermediate caches. In Express.js, you can set these headers using the res.set() method.

Can you give me an example of how to set cache headers in an Express route?

Sure! You can set cache headers like this:

app.get('/data', (req, res) => {
    res.set('Cache-Control', 'public, max-age=3600');
    res.json({ message: 'This data is cached for 1 hour.' });
});

What does 'max-age' mean in the Cache-Control header?

'max-age' specifies the maximum amount of time (in seconds) that the resource is considered fresh. After this time, the cache must revalidate the resource.

Are there any other cache-related headers I should know about?

Yes, other important headers include Expires, ETag, and Last-Modified. Each serves a different purpose in caching.