Concat 2 fields in JSON using jq

Question

I am using jq to reformat my JSON.

JSON String:

{"channel": "youtube", "profile_type": "video", "member_key": "hello"}

Wanted output:

{"channel" : "profile_type.youtube"}

My command:

echo '{"channel": "youtube", "profile_type": "video", "member_key": "hello"}' | jq -c '. | {channel: .profile_type + "." + .member_key}'

I know that the command below concatenates the string. But it is not working in the same logic as above:

echo '{"channel": "youtube", "profile_type": "video", "member_key": "hello"}' | jq -c '.profile_type + "." + .member_key'

How can I achieve my result using ONLY jq?

I think I'm trying to do exactly the same thing with my youtube API script ;) — Sridhar Sarnobat, Jan 20 '18 at 06:05

score 189 · Accepted Answer · edited Sep 24 '20 at 17:43

189

Use parentheses around the string concatenation code:

echo '{"channel": "youtube", "profile_type": "video", "member_key": "hello"}' \
 | jq '{channel: (.profile_type + "." + .channel)}'

edited Sep 24 '20 at 17:43

thanasisp

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answered Jun 08 '16 at 19:02

Anthony Battaglia

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Consider using string interpolation instead, much more cleaner than multiple string concatenations. – Jeff Mercado Jun 11 '16 at 08:06

score 86 · Answer 2 · edited Aug 23 '18 at 05:44

Here is a solution that uses string interpolation as Jeff suggested:

{channel: "\(.profile_type).\(.member_key)"}

e.g.

$ jq '{channel: "\(.profile_type).\(.member_key)"}' <<EOF
> {"channel": "youtube", "profile_type": "video", "member_key": "hello"}
> EOF
{
  "channel": "video.hello"
}

String interpolation works with the \(foo) syntax (which is similar to a shell $(foo) call).
See the official JQ manual.

Concat 2 fields in JSON using jq

2 Answers2

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