How can you connect backend with frontend?

Question

I want to make a website, and i wonder how you can get variables and other stuff from backend to frontend or reverse?

Answer 1

1. Inject them into your script in the backend. e.g in php
echo <<<_JS
<script>
window.my_vars = $var;
</script>
_JS;
This should not be used for private data like password.

2. To ensure privacy. You can call the backend script from frontend using ajax and work on the results in frontend. If you want to do that, search google for axios library or fetch api

3. You can use a service worker. The service worker can intercept http requests and perform logic between the backend and frontend. Not all browsers support service workers though

4. For things like extra form details you can use hidden inputs in html
<input type="hidden">

Answer 2

Thank you