使用JQ将json属性值级联到所有为null的子代

{
  "name": "John",
  "age": null,
  "address": {
    "street": null,
    "city": "New York",
    "country": null
  },
  "education": {
    "school": "ABC School",
    "degree": null
  }
}

jq 'recurse(. |= if type == "object" then with_entries(.value |= if . == null then "default value" else . end) else . end)' data.json

{
  "name": "John",
  "age": "default value",
  "address": {
    "street": "default value",
    "city": "New York",
    "country": "default value"
  },
  "education": {
    "school": "ABC School",
    "degree": "default value"
  }
}