Nodejs tutarial2

Promise

前端如何拿到后端数据?

在前后端通信过程中，一般使用一些异步机制来处理请求和响应 (更好的用户体验-不堵塞程序). 后端可以返回前端一个promise

Promise的三种情况

• pending: initial state, neither fulfilled nor rejected.

• fulfilled: meaning that the operation was completed successfully.

• rejected: meaning that the operation failed.