When is JavaScript synchronous?

Question

I have been under the impression for that JavaScript was always asynchronous. However, I have learned that there are situations where it is not (ie DOM manipulations). Is

Answer 1

To someone who really understands how JS works this question might seem off, however most people who use JS do not have such a deep level of insight (and don't necessarily need it) and to them this is a fairly confusing point, I will try to answer from that perspective.

JS is synchronous in the way its code is executed. each line only runs after the line before it has completed and if that line calls a function after that is complete ect...

The main point of confusion arises from the fact that your browser is able to tell JS to excute more code at anytime (simmlar to how you can excute more JS code on a page from the console). As an example JS has Callback functions who's purpose is to allow JS to BEHAVE asynchronously so further parts of JS can run while waiting for a JS function that has been executed (I.E. a GET call) to return back an answer, JS will continue to run until the browser has an answer at that point the event loop (browser) will execute the JS code that calls the callback function.

Since the event loop (browser) can input more JS to be executed at any point in that sense JS is asynchronous (the primary things that will cause a browser to input JS code are timeouts, callbacks and events)

I hope this is clear enough to be helpful to somebody.