如何使用javascript获取内部对象文字值

Question

After calling console.log(JSON.stringify(req.params)) , I get a string with the following structure:

{"q":"{\"email\":\"mymail@mail.com\"}","apiKey":"1234"}

With console.log(req.params.q) , I have this result: {"email":"mymail@mail.com"} . But I get "undefined" if I try to view the email value with console.log(req.params.q.email) or console.log(req.params.q["email"]) What is the best approach to get that value?

Answer 1

You must JSON.parse that inner part :

var test = {"q":"{\"email\":\"mymail@mail.com\"}","apiKey":"1234"};
alert(JSON.parse(test.q).email);

alerts mymail@mail.com

Why?

Because test holds an javascript object where q holds a string, So you must parse that string if you want to extract the JSON values from that string.

Answer 2

It looks like req.params.q is a string: "{\\"email\\":\\"mymail@mail.com\\"}" .

You need to parse that json then fetch the value.

req = {params: {"q":"{\"email\":\"mymail@mail.com\"}","apiKey":"1234"}}
JSON.parse(req.params.q)
> Object {email: "mymail@mail.com"}
JSON.parse(req.params.q).email
> "mymail@mail.com"