前端 - express里next()返回的状态是undefined？

Question

在做登陆注册模块。 在注册函数里，若没有输入用户名，则通过next中间件传去错误提示，这里没有抛出错误，所以http状态应该是200才对，但是却是undefined。 求指导。 app.js 错误提示

高洛峰 · Answer

This is an error in the send method. send only accepts one parameter.

PHPz · Answer

According to the error message given by the console, the first parameter of the send method must be a legal status code

天蓬老师 · Answer

The code is not truncated. Judging from the error message, there are two problems here

Key issue: The uploaded status is illegal. Just check the corresponding code.
Non-critical issue: res.send(status, body): This method is no longer recommended to be used in this way. The recommended usage method has been given in the error message.