JAVASCRIPT

new promise function

const myPromise = new Promise((resolve, reject) => {
  setTimeout(() => {
    resolve('foo');
  }, 300);
});

myPromise
  .then(handleResolvedA, handleRejectedA)
  .then(handleResolvedB, handleRejectedB)
  .then(handleResolvedC, handleRejectedC);

nodejs promise then example

p.then(onFulfilled, onRejected);

p.then(function(value) {
   //  run
  }, function(reason) {
  // fail
});

Creating a promise

JS
copy
let done = true

const isItDoneYet = new Promise((resolve, reject) => {
  if (done) {
    const workDone = 'Here is the thing I built'
    resolve(workDone)
  } else {
    const why = 'Still working on something else'
    reject(why)
  }
})

Making promises

new Promise((resolve, reject) => {
  if (ok) { resolve(result) }
  else { reject(error) }
})
 

Using Then To Create A Promise In JavaScript

async function abc()
{
Promise.resolve("hello world").then(function(value)
{
	console.log(value);
    }

javascript Program with a Promise

const count = true;

let countValue = new Promise(function (resolve, reject) {
    if (count) {
        resolve("There is a count value.");
    } else {
        reject("There is no count value");
    }
});

console.log(countValue);

Create A Promise In JavaScript

async function abc() 
{ 	
	const myPromise = new Promise(function(resolve, reject) {
   resolve("hello world");
});
let y= await myPromise;
console.log(y);
/*"hello world*/
	}

Create A Promise And Then Return It

let fetchSent =	fetch("/test", {method:"POST", body: JSON.stringify({name:"NAME NAME NAME"}), headers: {'Content-type': 'application/json; charset=UTF-8'}});
const p1 = new Promise((resolve, reject) => {
  resolve(fetchSent);
  // or
  // reject(new Error("Error!"));
})
	 

 return p1;
/*console.log(p1) will yield the fetch promise that was sent to you*/

javascript Create a Promise

let promise = new Promise(function(resolve, reject){
     //do something
});

making promises in js

getData()
    .then(data => console.log(data))
    .catch(error => console.log(error));