Do I need other languages except Javascript, CSS and HTML?

Question

What other programming languages do I need to create web app?

Answer 1

That's all you'll need for the front-end (what'll run on the browser). However there is also a back end (what runs on servers) and you'll need to know a back-end language (golang, PHP, Ruby, Python etc).

Answer 2

you may also need frameworks lile bootstrap..react..angular etc