如何从JSON字符串中检索多个属性值

Question

I have a JSON string:

x = '{"userId":"foo","traits":{"email":"foo@foobar.com"},"type":"identify"}'

that I want to get certain values from. I tried regex:

So far I have

anonId = x.match(/\"anonymous_id\"\:(.*?)/)?[1]
email = x.match(/\"email\"\:\"(.*?)\"/)?[1]
userId = x.match(/\"userId\"\:\"(.*?)\"/)?[1]
type = x.match(/\"type\"\:\"(.*?)\"/)?[1]

which is ugly and inefficient, but when I attempt to combine them:

[_, a, b, c, d] = x.match(/\"anonymous_id\"\:(.*?)|\"userId\"\:(.*?)|\"email\"\:(.*?)|\"type\"\:(.*?)/g)

the results that are returned are the entire group, instead of just the matched parts.

I want a,b,c,d to equal the value of keys, but instead I get:

Wanted:
**>> ["foo","foo@foobar.com","identify"]**
Actual results:
>> ["userId":"foo","email":"foo@foobar.com","type":"identify"]

Is there any way to achieve this in one line regex?

--- UDPATE ----

I ended up going with

  rxp = /\"user_id\"\:\"(.*?)\"|\"anonymous_id\"\:\"(.*?)\"|\"type\"\:\"(.*?)\"/g

  anonId = null
  userId = null
  type = null

  while (arr = rxp.exec(bdy)) isnt null
    userId = arr[1] if arr[1]
    anonId = arr[2] if arr[2]
    type = arr[3] if arr[3]

FWIW I'm avoiding using JSON.parse because I'm processing thousands of these and as I only need a small piece of it, I don't want the slowness of JSON.parse to impact the servers unnecessarily.

Answer 1

try {
   var parsed = JSON.parse(x);
   anonId = parsed.anonymous_id;
} catch (ex) {
  //invalid json
}

That should work unless you have invalid JSON coming in. And then you might want to consider Regex but even then you might want to look at templates.

Answer 2

Try using RegExp /[az@.]+(?=",|"})/ig at single call to .match()

 var x = '{"userId":"foo","traits":{"email":"foo@foobar.com"},"type":"identify"}'; var res = x.match(/[az@.]+(?=",|"})/ig); console.log(res);