JSON返回未定义的值

Question

I have a problem with a json output values returning undefined.

JSON:

[ { ID: 2, user: 'ngx.daniel', password: 'password', admin: 'F' } ]

CODE:

console.log(res);
res = JSON.stringify(res);
console.log(res);
var user = {};
user.user = res.user;
user.password = res.password;
user.admin = res.admin;
console.log(user);

OUTPUT:

[ RowDataPacket { ID: 2, user: 'ngx.daniel', password: 'password', admin: 'F' } ]
[ { ID: 2, user: 'ngx.daniel', password: 'password', admin: 'F' } ]
{ user: undefined, password: undefined, admin: undefined }

Answer 1

A few things. If this is your json:

[ RowDataPacket { ID: 2, user: 'ngx.daniel', password: 'password', admin: 'F' } ]

you dont need to stringify it. When you stringify it you turn your object into a string. you then try to access attributes of a string, which it doesnt have.
1 - Remove the stringify
2 - Thats an array thats being returned with a RowPacketData object, which is also invalid json.
3 - To access an object in an array you need to first access the index. So it should really be something like

(if res = [ { ID: 2, user: 'ngx.daniel', password: 'Root_!$@#', admin: 'F' }] )

var user = {};
user.user = res[0].user;
user.password = res[0].password;
user.admin = res[0].admin;

Answer 2

The response can apparently consist of multiple items ( RowDataPackets ). You can get the first via index 0. And there is no need to stringify the response:

console.log(res);
var user = {};
user.user = res[0].user;
user.password = res[0].password;
user.admin = res[0].admin;
console.log(user);

Which prints

Object { user="ngx.daniel", password="Root_!$@#", admin="F"}