javascript promise with jquery code example

Example 1: .promise()

var promise = new Promise(function(resolve, reject) {
  // do some long running async thing…
  
  if (/* everything turned out fine */) {
    resolve("Stuff worked!");
  }
  else {
    reject(Error("It broke"));
  }
});

Example 2: jquery ajax promise

$.ajax({
    url: "/someurl",
    method: "GET",
    data: { 
      a: "a"
  })
  .done(function(data) {
    console.log('success callback 1', data) 
  })
  .done(function(data) {
    console.log('success callback 2', data) 
  })
  .fail(function(xhr) {
    console.log('error callback 1', xhr);
  })
  .fail(function(xhr) {
    console.log('error callback 2', xhr);
  });