promise syntax for javascript

1/*
2	A Promise is a proxy for a value not necessarily known when the promise is created. 
3    It allows you to associate handlers with an asynchronous action's eventual success 
4    value or failure reason.
5*/            
6let promise = new Promise((resolve , reject) => {
7  fetch("https://myAPI")
8    .then((res) => {
9      // successfully got data
10      resolve(res);
11    })
12    .catch((err) => {
13      // an error occured
14      reject(err);
15    });          
16});

1const myPromise = new Promise((resolve, reject) => {
2  setTimeout(() => {
3    resolve('foo');
4  }, 300);
5});
6
7myPromise
8  .then(handleResolvedA, handleRejectedA)
9  .then(handleResolvedB, handleRejectedB)
10  .then(handleResolvedC, handleRejectedC);
11

1let promise = new Promise(function(resolve, reject){
2  try{
3  	resolve("works"); //if works
4  } catch(err){
5    reject(err); //doesn't work
6  }
7}).then(alert, console.log); // if doesn't work, then console.log it, if it does, then alert "works"

1let myPromise = new Promise(function(myResolve, myReject) {
2// "Producing Code" (May take some time)
3
4  myResolve(); // when successful
5  myReject();  // when error
6});
7
8// "Consuming Code" (Must wait for a fulfilled Promise)
9myPromise.then(
10  function(value) { /* code if successful */ },
11  function(error) { /* code if some error */ }
12);