Deferred.js

function Deferred() {
  this.resolve = null;
  this.reject = null;

  this.promise = new Promise((resolve, reject) => {
    this.resolve = resolve;
    this.reject = reject;
  });
}


var d = new Deferred();

  d.promise.then(x => {
    console.log("ok");
  }).catch(x => {
    console.log("failed");
  });



console.log("start");

d.resolve();
//d.reject();

console.log("end");