如何將一個承諾的結果保存到一個變量，并將其傳遞到另一個函數？

您的數據需要有一個async構造函數（可以說是奇數）或await，因為每個async函數都隱式地是一個承諾，即使它同步地返回一個值。。。所以：

function CalendarPicker() {
  //Get meeting data ... then
  _getMeetingsData().then(meetingsData => {
    this.meetingsData = meetingsData;
    this._insertNavigationButtons();
    this._insertHeaderIntoCalendarWrapper();
    this._insertCalendarGridDaysHeader();
    this._insertDaysIntoGrid();
    this._insertCalendarIntoWrapper();
  });
}

這是可行的，但如果您有任何需要該數據的原型方法，則最好存儲以下承諾：

function CalendarPicker() {
  //Get meeting data ... then
  this._meetingsData = _getMeetingsData().then(meetingsData => {
    this.meetingsData = meetingsData;
    this._insertNavigationButtons();
    this._insertHeaderIntoCalendarWrapper();
    this._insertCalendarGridDaysHeader();
    this._insertDaysIntoGrid();
    this._insertCalendarIntoWrapper();
  });
}

CalendarPicker.prototype.doThings = function () {
  this._meetingsData.then(() => {
    console.log(this.meetingsData);
  });
};