Promis.then()

    function cook() {
      console.log('开始做饭。');
      var p = new Promise(function (resolve, reject) {
        setTimeout(function () {
          console.log('做饭完毕！');
          resolve('鸡蛋炒饭');
        }, 1000);
      });
      return p;
    }

    function eat(data) {
      console.log('开始吃饭：' + data);
      var p = new Promise(function (resolve, reject) {
        setTimeout(function () {
          console.log('吃饭完毕!');
          resolve('一块碗和一双筷子');
        }, 2000);
      });
      return p;
    }
    function wash(data) {
      console.log('开始洗碗：' + data);
      var p = new Promise(function (resolve, reject) {
        setTimeout(function () {
          console.log('洗碗完毕!');
          resolve('干净的碗筷');
        }, 2000);
      });
      return p;
    }

    cook()
      .then(eat)
      .then(wash)
      .then(function (data) {
        console.log(data);
      });

输出：

备注：resolve只能传入一个参数，传入的其它参数，读取到的值为"undefined"。