How do I extract a key with jq based on its child values

Question

I\'m trying to process some JSON with jq. Specifically, I want a particular key, based on its child value. Example, given:

{
  \"foo\": {\"primary\": true, \"b         


        

Answer 1

You need to "split" your object into an array of entries, e.g.

[
  {
    "key": "foo",
    "value": {
      "primary": true,
      "blah": "beep"
    }
  }
  //...
]

Then you can filter with .value.primary and map the result with .key:

to_entries | map(select(.value.primary)  | .key)

Returns:

[
  "foo"
]

Or to get just the first item of the array: (Thanks @nbari)

to_entries | map(select(.value.primary)  | .key)[0]