Add JSON to empty array issue

Question

I have a top level JSON structure as follows:

{
    "video": [],
    "messages": [],
    "notifications": []
}

and i have a database output (in variable "result") as follows i want to push into the "video" array:

[
    {
        "_id": "5f98ab906439155cfc6f9afb",
        "status": "NOT_STARTED",
        "date": "2020-10-27T23:21:52.683Z",
        "callInvitees": [
            {
                "username": "user1"
            },
            {
                "username": "user2"
            }
        ]
    },
    {
        "_id": "5f98aba0789e163e0c78908f",
        "status": "NOT_STARTED",
        "date": "2020-10-27T23:22:08.048Z",
        "callInvitees": [
            {
                "username": "user1"
            }
        ]
    }
]

My code is:

let dashboardJSON = { "video": [], "messages": [], "notifications": [] };
dashboardJSON.video.push(result)

It works but i am ending up with too many arrays (i think) - it looks as follows:

{
    "video": [
        [
            {
                "_id": "5f98ab906439155cfc6f9afb",
                "status": "NOT_STARTED",
                "date": "2020-10-27T23:21:52.683Z",
                "callInvitees": [
                    {
                        "username": "user1"
                    },
                    {
                        "username": "user2"
                    }
                ]
            },
            {
                "_id": "5f98aba0789e163e0c78908f",
                "status": "NOT_STARTED",
                "date": "2020-10-27T23:22:08.048Z",
                "callInvitees": [
                    {
                        "username": "user1"
                    }
                ]
            }
        ]
    ],
    "messages": [],
    "notifications": []
}

I want "video": [ { ... }, { ... } ] whereas i have "video": [[ { ... }, { ... } ]]

How can i resolve this?

Majed Badawi · Accepted Answer · 2020-11-01 17:20:31Z

1

You can use the spread operator as follows:

let result = [
    {
        "_id": "5f98ab906439155cfc6f9afb",
        "status": "NOT_STARTED",
        "date": "2020-10-27T23:21:52.683Z",
        "callInvitees": [
            {
                "username": "user1"
            },
            {
                "username": "user2"
            }
        ]
    },
    {
        "_id": "5f98aba0789e163e0c78908f",
        "status": "NOT_STARTED",
        "date": "2020-10-27T23:22:08.048Z",
        "callInvitees": [
            {
                "username": "user1"
            }
        ]
    }
]

let dashboardJSON = { "video": [], "messages": [], "notifications": [] };

dashboardJSON.video.push(...result)

console.log(dashboardJSON);

edited Nov 1, 2020 at 17:20

answered Nov 1, 2020 at 17:10

Majed Badawi

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2 Comments

Kevin Over a year ago

Amazing, thankyou! What is the "spread operator" doing?

Majed Badawi Over a year ago

@Kevin you are welcome. It's expanding the items of result to be pushed individually instead of a list of objects.

phi-rakib · Accepted Answer · 2020-11-01 17:20:25Z

0

Just use Array.prototype.map() method. Map method returns a new array with the result by using the provided function.

const ret = {
  video: [],
  messages: [],
  notifications: [],
};

const data = [
  {
    _id: '5f98ab906439155cfc6f9afb',
    status: 'NOT_STARTED',
    date: '2020-10-27T23:21:52.683Z',
    callInvitees: [
      {
        username: 'user1',
      },
      {
        username: 'user2',
      },
    ],
  },
  {
    _id: '5f98aba0789e163e0c78908f',
    status: 'NOT_STARTED',
    date: '2020-10-27T23:22:08.048Z',
    callInvitees: [
      {
        username: 'user1',
      },
    ],
  },
];

ret.video = data.map((x) => x);
console.log(ret);

edited Nov 1, 2020 at 17:20

answered Nov 1, 2020 at 17:09

phi-rakib

3,3222 gold badges12 silver badges21 bronze badges

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