promise-example.js

const asyncThingWithPromise = () => {
 var promise = new Promise((resolve, reject) => {
    try{
      // do something async here. Like get data from a server or read a file from disk etc.
      var value = 'My Async Data'; 
      resolve(value) // handled by promise's then()
    }catch(error){
      reject(error) // handled by promise's catch()
    }
 });
  return promise;
}


// usage
asyncThingWithPromise()
  .then(value => console.log(value))
  .catch(error => console.error(error));