JavaScript example of using promises and callbacks

promise_callback.js

var promiser = function (callback) {
  var promise = new Promise(function(resolve, reject){
    console.log("Promise created");
    window.setTimeout(function(){
      resolve("Hello from Promise Land");
    }, 3000);
  });
  
  promise.then(function(){
    callback();
  });
};

var myCallback = function () {
  console.log("Promise resolved"); 
};

promiser(myCallback);