Javascript or lodash nested JSON object transformation

Question

How to make nested object null

if object attributes has a null values. please check the JSON below

I have JSON data as following

[{
    "student": {
        "id": null,
        "name": null
    },
    "children": [{
        "student": null,
        "children": [{
                "student": {
                    "id": 1,
                    "name": "A"
                }
            },
            {
                "student": {
                    "id": null,
                    "name": null
                }
            }
        ]
    }]
}]

I want to convert it to following output

Expected

[{
    "student": null,
    "children": [{
        "student": null,
        "children": [{
                "student": {
                    "id": 1,
                    "name": "A"
                }
            },
            {
                "student": null
            }
        ]
    }]
}]

Answer 1

You could "nullify" values if their values are all null using the following conditional.

Object.values(obj).every(value => value == null)

I created a basic recursive function to below that traverses the object and checks to see if it needs to nullify an object. This is all done in-place, and it will modify the original object.

const obj = [{
  "student": { "id": null, "name": null },
  "children": [{
    "student": null,
    "children": [
      { "student": { "id": 1, "name": "A" } },
      { "student": { "id": null, "name": null } }
    ]
  }]
}];

const nullify = (obj, key = null, parent = null) => {
  if (obj != null) {
    if (Array.isArray(obj)) {
      obj.forEach((item, index) => nullify(item, index, obj));
    } else if (typeof obj === 'object') {
      if (Object.values(obj).every(value => value == null)) {
        parent[key] = null;
      } else {
        Object.entries(obj).forEach(([key, value]) => nullify(value, key, obj));
      }
    }
  }
};

nullify(obj);

console.log(obj);

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