parse JSON and malipulate its object values

Question

I have a json file named xyz.json as follows

[
    {
        "annotations": [ "a" , "b" , "c" ],
        "class": "image",
        "filename": "vc00_02201.png"
    },
    {
        "annotations": [],
        "class": "image",
        "filename": "vc00_02202.png"
    }
    {
        "annotations": [],
        "class": "image",
        "filename": "vc00_02203.png"
    },
    {
        "annotations": [],
        "class": "image",
        "filename": "vc00_02204.png"
    }
]

I need to copy the object "annotations" from "filename": "vc00_02201.png" to "annotations" of "filename": "vc00_02204.png" within the same xyz.json file using a shell script. Expected output:

[
    {
        "annotations": [ "a" , "b" , "c" ],
        "class": "image",
        "filename": "vc00_02201.png"
    },
    {
        "annotations": [],
        "class": "image",
        "filename": "vc00_02202.png"
    }
    {
        "annotations": [],
        "class": "image",
        "filename": "vc00_02203.png"
    },
    {
        "annotations": [ "a" , "b" , "c" ],
        "class": "image",
        "filename": "vc00_02204.png"
    }
]

Answer 1

$cat xyz.json | jq '.[3].annotations=.[0].annotations'

Answer 2

this is also achievable via jtc in one line:

bash $ cat xyz.json | jtc -w'<vc00_02204.png>[-1][annotations]' -eu jtc -w'<vc00_02201.png>[-1][annotations]' xyz.json \; 
[
   {
      "annotations": [
         "a",
         "b",
         "c"
      ],
      "class": "image",
      "filename": "vc00_02201.png"
   },
   {
      "annotations": [],
      "class": "image",
      "filename": "vc00_02202.png"
   },
   {
      "annotations": [],
      "class": "image",
      "filename": "vc00_02203.png"
   },
   {
      "annotations": [
         "a",
         "b",
         "c"
      ],
      "class": "image",
      "filename": "vc00_02204.png"
   }
]
bash $ 

Of course, it could have been done via referencing direct members of array, like:

bash $ cat xyz.json | jtc -w'[3][annotations]' -eu jtc -w'[0][annotations]' xyz.json \;

but then whole point of cross-referencing by filename would be moot.