How do I make a text area get compiled by a programming language then output gets logged

Issue

How do I have a text area as input, compile it with nothing like javascript, and use the console logs as output?

Solution

Most likely they have a 'backend' / API, which is a separate environment from your browser and HTML, and is a program running on some server. In your browser, Javascript can take your input, send it to the server and then the server and run the code and send it back to Javascript.

This is not possible with HTML alone.

Answered By - Evert