Javascript SetTimeout asynchronomous Test...

async.js

var changed = false;

setTimeout(function () {
  console.log("I'm hacking in setTimeout~~~");
  changed = true;
})

while (true) {
  if (changed) {
    console.log("The system has been hacked by outer program. Exiting...");
    break;
  }
}

setTimeout(function () {
  console.log(`The value of $changed: ${changed}`);
})