two-argument then

promises.js

promise.then((result) => {
  // promise resolved successfully.
  console.log(`Result is ${result}`);
}, (error) => {
  // promise was failed
  console.log(`Error is ${error}`);
});

// Also: promise.then(null, (error) => { ... }) is the same as promise.catch((error) => { ... }).
// The Promise#catch method is just a convenience. You can always just pass a null success handler to then.