Javascript – How to Flatten a nested JSON object

I have a Nested JSON input as shown below which I want to flatten into expected output.
Key won’t be always the same eg: u_summary, created_date, u_product i.e. there could be even more keys.

Any help?

JSON Nested input:

var jsonUnflattenInput = 
    [
        
        {
            "u_summary": {
                "display_value": "Please check the data and set the company accordingly if everything is fine.",
                "value": "Please check the data."
            },
            "created_date": {
                "display_value": "2022-06-18 11:45:00",
                "value": "2022-05-29 21:42:01"
            },
            "u_product": {
                "display_value": "Undefined",
                "value": "2345567"
            }
        },
        {
            "u_summary": {
                "display_value": "╓ tool v14.3",
                "value": "14.3"
                },
            "created_date": {
                "display_value": "2022-03-18 11:45:00",
                "value": "2022-02-29 21:42:01"
            },
            "u_product": {
                "display_value": "test_product",
                "value": "1367"
            }
        }
    ]

Expected JSON Output:

[
    {
        "dv_u_summary": "Please check the data and set the company accordingly if everything is fine.",
        "u_summary": "Please check the data.",
        "dv_created_date": "2022-06-18 11:45:00",
        "created_date": "2022-05-29 21:42:01",
        "dv_u_product": "Undefined",
        "u_product": "2345567"
    },
    {
        "dv_u_summary": "╓ tool v14.3",
        "u_summary": "14.3",
        "dv_created_date": "2022-03-18 11:45:00",
        "created_date": "2022-02-29 21:42:01",
        "dv_u_product": "test_product",
        "u_product": "1367"
    }
]

I tried the below code after referring to some blogs, but couldn’t get the expected output.

function flatten(json, flattened, str_key) {
                for (var key in json) {
                  if (json.hasOwnProperty(key)) {
                    if (json[key] instanceof Object && json[key] != "") {
                      flatten(json[key], flattened, str_key + "." + key);
                    } else {
                      flattened[str_key + "." + key] = json[key];
                    }
                  }
                }
            }

        var flattened = {};
         
        flatten(jsonUnflattenInput, flattened, "");
        

        for (var key in flattened){
          console.log(key + ": " + flattened[key]);
        }

>Solution :

function flatten(json) {
  var newJSON = [];
  for (var i = 0; i < json.length; i++) {
    var obj = {};
    for (var key in json[i]) {
      if (json[i].hasOwnProperty(key)) {
        obj['dv_' + key] = json[i][key]['display_value'];
        obj[key] = json[i][key]['value'];
      }
    }
    newJSON.push(obj);
  }
  return newJSON;
}

var jsonUnflattenInput = [

  {
    "u_summary": {
      "display_value": "Please check the data and set the company accordingly if everything is fine.",
      "value": "Please check the data."
    },
    "created_date": {
      "display_value": "2022-06-18 11:45:00",
      "value": "2022-05-29 21:42:01"
    },
    "u_product": {
      "display_value": "Undefined",
      "value": "2345567"
    }
  },
  {
    "u_summary": {
      "display_value": "╓ tool v14.3",
      "value": "14.3"
    },
    "created_date": {
      "display_value": "2022-03-18 11:45:00",
      "value": "2022-02-29 21:42:01"
    },
    "u_product": {
      "display_value": "test_product",
      "value": "1367"
    }
  }
]

console.log(flatten(jsonUnflattenInput))

This should work for the provided example data.