Append new keys to a JSON array

Question

I have this JSON array that Zabbix retrieves as a string and each object has the keys "startTime" and "endTime" which are date-time strings in the format of "DD-MM-YYYY HH:mm:ss".

Using Javascript, I'm trying to add a new key to each object in the array. The new key is called "execTime" and it should have a value equal to the difference between "endTime" and "startTime" in seconds.

Input JSON sample:

[
    {
    "endTime": "02-02-2024 10:10:20",
    "startTime": "02-02-2024 10:10:10",
    },
    {
    (...)
    }
]

Expected output JSON:

[
    {
    "endTime": "02-02-2024 10:10:20",
    "startTime": "02-02-2024 10:10:10",
    "execTime": 10
    },
    {
    (...)
    }
]

For that, I was trying to use the following script.

function (value) {
    const jsonValue = JSON.parse(value);

    for (var i = 0; i < jsonValue.length; i++) {
      const startDate = new Date(jsonValue[i].startTime);
      const endDate = new Date(jsonValue[i].endTime);

      const execTime = ( endDate.getTime() - startDate.getTime() ) / 1000;
      if ( execTime < 0 ) { var execTime = 0; }
      jsonValue[i].execTime = execTime;
    };

    return jsonValue;
}

The problem is that the return value is this:

[object Object],[object Object],[object Object], (...)

Any thoughts on this?

Answer 1

return JSON.stringify(jsonValue);

// Convert the result back to a JSON-formatted string