How do loop through nested json object with javascript?

March 16, 2023

Struggling with iterating through the following return json string from an API:

{
"data": [
{
  "ActionNeeded": null,
  "OldestStatus": null,
  "ServiceHost": "W501",
  "ServiceName": "Renewals",
  "ServiceStatusDateTime": "2023-03-15T22:47:05.313000",
  "ServiceVersion": "1.0.0",
  "SortOrder": "0",
  "TimeAgo": null
},
{
  "ActionNeeded": null,
  "OldestStatus": null,
  "ServiceHost": "W202",
  "ServiceName": "Monitor",
  "ServiceStatusDateTime": "2023-03-15T22:46:42.560000",
  "ServiceVersion": null,
  "SortOrder": "1",
  "TimeAgo": null
},
{
  "ActionNeeded": null,
  "OldestStatus": null,
  "ServiceHost": "W0070204",
  "ServiceName": "Monitor",
  "ServiceStatusDateTime": "2023-03-15T22:46:39.840000",
  "ServiceVersion": "2.0.2",
  "SortOrder": "1",
  "TimeAgo": null
}
]
]

I’ve tried a for..in loop, but am only managing to get the first "set" of key/value pairs.

Here is my current code:

var json_obj = JSON.parse(event.data);

// Returned records
const items = json_obj['data'];

for (var item_index in items) {
    if (items.hasOwnProperty(item_index)) {
        console.log(item_index);
    }
}

How can I loop through each "set" of data and out both key and value?

>Solution :

To loop through the nested JSON object provided, you can use JavaScript’s forEach loop. In this example, the JSON object has a property called data which contains an array of objects. You can loop through each object in the array and access its properties like this:

const jsonObject = {
  "data": [
    //... your JSON data
  ]
};

// Loop through the data array
jsonObject.data.forEach((item) => {
  console.log('ActionNeeded:', item.ActionNeeded);
  console.log('OldestStatus:', item.OldestStatus);
  console.log('ServiceHost:', item.ServiceHost);
  console.log('ServiceName:', item.ServiceName);
  console.log('ServiceStatusDateTime:', item.ServiceStatusDateTime);
  console.log('ServiceVersion:', item.ServiceVersion);
  console.log('SortOrder:', item.SortOrder);
  console.log('TimeAgo:', item.TimeAgo);
  console.log('-------------------');
});

If you don’t know the property names in advance you can do like this:

for (const item of jsonObject.data) {
  // Loop through the keys and values of the current item
  for (const [key, value] of Object.entries(item)) {
    console.log(`${key}: ${value}`);
  }
  console.log('-------------------');
}