In addition to what the rest of the comments are saying: if you're talking about front-end Javascript, take the time to really learn the devtools in your browse

In addition to what the rest of the comments are saying: if you're talking about front-end Javascript, take the time to really learn the devtools in your browser of choice (personally I'd recommend Chrome or Chromium, but I'll grant that I don't have a whole lot of experience with Firefox.) It's basically an entire IDE right there waiting for you to use. (With a little bit of futzing, you can even use the Chrome devtools as a debugger for Node.JS, which absolutely blew my mind when I first gave it a shot.)