How to print object element for each internal array element in jq.md

Query: How to print object element for each internal array element in jq

(jump to the answer)

I have JSON that looks like this:

test.json

[
  {
    "item1": {
      "item2": 123,
      "array1": [
        {
          "item3": 456,
          "item4": "teststring"
        },
        {
          "item3": 789,
          "item4": "teststring2"
        }
      ]
    }
  }
]

I am trying to print it out in the following format:

123, 456, teststring
123, 789, teststring2

I tried to do it like this:

cat test.json | jq -r '.[].item1.item2, (.[].item1.array1[] | .item3, .item4)' | xargs printf "%s, %s, %s\n"

But the result is that item2 is printed, followed by item3 and item4 in the first line, and then only item3 and item4 are printed in the next line, like so:

123, 456, teststring
789, teststring2, 

How can I make the element on the outside of the array print for every set of elements that are printed from within the array?

A:

with jtc the ask is quite trivial:

bash $ <test.json jtc -w'<item2>l<I>v[-1][array1][:]' -qqT'"{I}, {}"'
123, 456, teststring
123, 789, teststring2
bash $ 

- <item2>l<I>v: find recursively a value by the label "item2" and memorize it (in I)
- [-1][array1][:]: step up 1 tier in the JSON tree, select "array1" and then select each array
- -qqT'"{I}, {}"': in the template interpolate memorized valie in I and then each walked array

if there's a reqiurement to keep string literals quoted, then use this form:

bash $ <test.json jtc -w'<item2>l<I>v[-1][array1][:]' -qqT'"{I}, {$a}, \"{$b}\""'
123, 456, "teststring"
123, 789, "teststring2"
bash $ 

if some value type in a column is non-consistent i.e., could be a JSON string in one row and a non-string value in another, (like modified JSON below) and there's a requirement to keep the original format type, then use this template format:

bash $ <test.json jtc 
[
   {
      "item1": {
         "array1": [
            {
               "item3": 456,
               "item4": "teststring"
            },
            {
               "item3": 789,
               "item4": null
            }
         ],
         "item2": 123
      }
   }
]
bash $ 
bash $ <test.json jtc -w'<item2>l<I>v[-1][array1][:]' -qqT'"{I}, {$a}, >{{$b}}<"'
123, 456, "teststring"
123, 789, null
bash $ 

• stringification >{{$b}}< ensures that quotation marks will be preserved in case if it's a string value, and thus upon jsonization (-qq) will be shown