Promise example

promise-example.js

var p = new Promise(function(resolve, reject) {

	if(1 === 1) { // set 1===2 to make it fail
		resolve('Success!');
	}
	else {
		reject('Failure!');
	}
});

p.then((success) => console.log(success), (fail) => console.log(fail));


// .then takes two callbacks. the first has an argument that will be the successful result, and the second has an argument that will be the reason for failure.




// chaining catch after then is the same as passing a second callback to .then to handle the error.
var p = new Promise(function(resolve, reject) {
	// A mock async action using setTimeout
	setTimeout(function() { reject('Done!'); }, 1000);
});

// the same as...
p.then(function(e) { console.log('done', e); })
.catch(function(e) { console.log('catch: ', e); });








p.then(function(e) { console.log('done', e); },function(e) { console.log('catch: ', e); })



var data =[
  { id: 0, name: 'Luke Skywalker' },
  { id: 1, name: 'Batman' },
  { id: 2, name: 'Boba Fett' }
];

var promise = new Promise(function(resolve,reject){
  setTimeout(function(){ resolve(data); },4000);
});


promise.then(function(data){
  console.log(data);
}).catch(function(error){
  console.log(error);
});

var promise2 = new Promise(function(resolve, reject) {
  if (1===2) {
    resolve("Stuff worked!");
  }
  else {
    reject("this shit didnt work");
  }
});

promise2.then(function(data){
  console.log(data);
}).catch(function(error){
  console.log(error);
});