[异步函数表达式](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Operators/async%E5%85%81%E8%AE%B8%E5%A3%B0%E6%98%8E%E4%B8%80%E4%B8%AA%E5%87%BD%E6%95%B0%E4%B8%BA%E4%B8%80%E4%B8%AA%E5%8C%85%E5%90%AB%E5%BC%82%E6%AD%A5%E6%93%8D%E4%BD%9C%E7%9A%84%E5%87%BD%E6%95%B0 "async function 关键字用来在表达式中定义异步函数。当然，你也可以用 异步函数语句 来定义。")