Simplest example of a promise

simple-promise.md

let promiseToClean = new Promise(function( resolve, reject) { 
  // cleaning the room 
  
  let isClean = false;
  
  if (isClean){
    resolve('Clean');
  } else {
    reject('not Clean');
  }
})

The Caller:

promiseToClean.then(function() {
    console.log('the room is clean')
}).catch(function() {
    console.log('the room is not clean')
})