How to get key names from JSON using jq

Question

curl http://testhost.test.com:8080/application/app/version | jq \'.version\' | jq \'.[]\'

The above command outputs only the values as below:

Answer 1

To get the keys on a deeper node in an JSON:

echo '{"data": "1", "user": { "name": 2, "phone": 3 } }' | jq '.user | keys[]'
"name"
"phone"