jq - How to iterate through keys of different names

Question

I've got JSON that looks like this

{
  "keyword1": {
    "identifier1": 16
  },
  "keyword2": {
    "identifier2": 16
  }
}

and I need to loop through the keywords to get the identifiers (not sure if I'm using the right terminology here). Seems pretty simple, but because the keywords are all named different, I don't know how to handle that.

Please specify what you want the output to look like. – Mark Reed Jan 30 '16 at 04:09 — Mark Reed, Jan 30 '16 at 04:09
Just like the answer from peak – Adam vonNieda Feb 01 '16 at 02:25 — Adam vonNieda, Feb 01 '16 at 02:25

peak · Accepted Answer · 2020-08-10T01:16:37.943

43

The original tag for this question was jq so here is a jq solution:

.[] | keys[]

For example, with the input as shown in the question:

$ jq '.[] | keys[]' input.json

"identifier1"
"identifier2"

To retrieve the key names in the order they appear in the JSON object, use keys_unsorted.

edited Aug 10 '20 at 01:16

answered Jan 29 '16 at 18:25

peak

88,177
15
123
150

Neat, I didn't know that you could turn an object into an array with `[]`. – Mark Reed Feb 01 '16 at 14:21

score 18 · Answer 2 · answered May 28 '20 at 23:18

18

I'd think something along these lines would work well:

jq '. | to_entries | .[].key'

see https://stedolan.github.io/jq/manual/#to_entries,from_entries,with_entries

or if you wanted to get the values from a variable:

JSON_DATA={main:{k1:v1,k2:v2}}
result=$(jq -n "$JSON_DATA" | jq '.main | to_entries | .[].value' --raw-output)
echo $result

##outputs: v1 v2

answered May 28 '20 at 23:18

bristweb

490
6
10

1

Usage of `to_entries` was very helpful! – Mark Schäfer Jul 21 '20 at 09:04

score 5 · Answer 3 · answered Jan 08 '19 at 00:57

I came here hoping to sort out a bunch of keys from my JSON, I found two features handy. There are three functions "to_entries", "from_entries", and "with_entries". You can filter the values by key or value, like so:

JSON_DATA='
{
  "fields": {
    "first": null,
    "second": "two",
    "third": "three"
  }
}
'

echo "$JSON_DATA" | jq '{fields: .fields | with_entries(select(.value != null and .key != "third")) }'

Output:

{
  "fields": {
    "second": "two"
  }
}

jq - How to iterate through keys of different names

3 Answers3