Is google apps script synchronous?

Question

I'm a Java developer learning JavaScript and Google Apps Script simultaneously. Being the newbie I learned the syntax of JavaScript, not how it actually worked and I happily hacked away in Google Apps Script and wrote code sequentially and synchronous, just like Java. All my code resembles this: (grossly simplified to show what I mean)

function doStuff() {
  var url = 'https://myCompany/api/query?term<term&search';
  var json = getJsonFromAPI(url);
  Logger.log(json);
}

function getJsonFromAPI(url) {
  var response  = UrlFetchApp.fetch(url);
  var json = JSON.parse(response);
  return json;
}

And it works! It works just fine! If I didn't keep on studying JavaScript, I'd say it works like a clockwork. But JavaScript isn't a clockwork, it's gloriously asynchronous and from what I understand, this should not work at all, it would "compile", but logging the json variable should log undefined, but it logs the JSON with no problem.

NOTE:

The code is written and executed in the Google Sheet's script editor.

Why is this?

Answer 1

While Google Apps Script implements a subset of ECMAScript 5, there's nothing forcing it to be asynchronous.

While it is true that JavaScript's major power is its asynchronous nature, the Google developers appear to have given that up in favor of a simpler, more straightforward API.

UrlFetchApp methods are synchronous. They return an HttpResponse object, and they do not take a callback. That, apparently, is an API decision.