此Node Javascript单行条件有什么问题？

Question

这里是：

( result.username === user.username ) ? res.status( 500 ).json( "That username is already taken." ) : res.status( 500 ).json( "That email has already been used." )

如果条件为真， res.status( 500 ).json( "That username is already taken." )是否不应该做第一件事res.status( 500 ).json( "That username is already taken." ) ？ 相反，它说：

[TypeError: undefined is not a function]

---

这按预期工作。

if ( result.username === user.username ) return res.status( 500 ).json( "That username is already taken." )
else return res.status( 500 ).json( "That email has already been used." )

抱歉，如果我仍然没有发现错字。

Answer 1

可以使用以下代码：

var express = require('express');
var app = express();

app.get('/', function (req, res) {   
    (true) ? res.status( 500 ).json( "That username is already taken.") : res.status( 500 ).json( "That email has already been used." )
});

var server = app.listen(9000, function () {

var host = server.address().address;
var port = server.address().port;

console.log('Example app listening at http://%s:%s', host, port);

});

Answer 2

json（）中的字符串不是JSON格式，请尝试：

res.status( 500 ).json({msg:"That username is already taken."})