SOURCE

// 获取topic_id为592917b59e32cc84569a7458的主题信息
function getTopicInfo1(deferred) {
  $.ajax({
    type: 'GET',
    url: 'https://cnodejs.org/api/v1/topic/592917b59e32cc84569a7458',
    success: res => {
      deferred.resolve(res);
    },
    error: err => {
      deferred.resolve(err);
    }
  })
}
// 获取topic_id为58eee565a92d341e48cfe7fc的主题信息
function getTopicInfo1() {
  $.ajax({
    type: 'GET',
    url: 'https://cnodejs.org/api/v1/topic/58eee565a92d341e48cfe7fc',
    success: res => {
      deferred.resolve(res);
    },
    error: err => {
      deferred.resolve(err);
    }
  })
}

$(document).ready(() => {
  let topic1Deffer = $.Deferred();
  let topic2Deffer = $.Deferred();

  $.when(topic1Deffer, topic2Deffer).done(function(topic1, topic2) {
    console.log(topic1);
    console.log(topic2);
  });
})

<script src="http://cdn.bootcss.com/zepto/1.0rc1/zepto.min.js"></script>
<script src="http://fs.andylistudio.com/blog/deffer.js"></script>
<script src="http://fs.andylistudio.com/blog/callback.js"></script>