Delays With Callback Hell in JavaScript

delays-with-callback-hell.js

const delay = (ms, result, cb) => setTimeout(() => cb(result), ms);

function delays() {
  delay(800, "Hello, I'm in a", a => {
    console.log(a);
    delay(400, "callback!", b => {
      console.log(b);
    });
  });
}

// call it
delays();