Promises in JavaScript with examples

Promises.js

/*
* ** Diffrence between Tasks and Promises:
* Once settled, a promise can not be resettled. Calling resolve() or reject() again will have no effect. The immutability of a settled promise is an important feature.
* https://medium.com/javascript-scene/master-the-javascript-interview-what-is-a-promise-27fc71e77261
* *** First arg is for 'resolved' status, and the second is for 'rejected'
*/

// exampe 1
const myPromise = function () {
  return new Promise((Yay, Nay) => {
    // Uncomment whatever state you want to return, first one to fire is the return.
    // Yay()
    Nay()
    console.log('after message');

  })
}

myPromise()
.then(() => console.log('RESOLVED'))
.catch(() => console.log('REJECTED'))

// example2 with passed value
const myPromise2 = function (n) {
  return new Promise((Yay, Ops) => {
    if (n < 10) {
      Yay('I\'m Resolved') // Passing argument to be used by 'then'
    } else {
      Ops('I\'m Rejected')
    }
  })
}

myPromise2(50)
.then(resolveResponse => console.log('RESOLVED:', resolveResponse)) // "RESOLVED: I'm Resilved"
.catch(rejectResponse => console.log('REJECTED:', rejectResponse)) // "REJECTED: I'm Rejected"

// third one just for fun
const myPromise3 = function () {
  return new Promise((Yay, Nay) => {
    // Uncomment whatever state you want to return
    Yay()
    // Nay()
  })
}

myPromise3()
.then(() => console.log('RESOLVED'))
.catch(() => console.log('REJECTED'))

const myPromise4 = function (n) {
  return new Promise((Yay, Ops) => {
    if (n < 10) {
      Yay('I\'m Resolved4')
    } else {
      Ops('I\'m Rejected4')
    }
  })
}

myPromise4(50)
.then(resolveResponse => console.log('RESOLVED:', resolveResponse))
.catch(rejectResponse => console.log('REJECTED:', rejectResponse))

console.log('Even though i\'m at EOF, I appear first because Promises seems to be gone to the next event loop');