Nested array filtering in lodash

Question

I have a Json Like this -

[
    {
        "place": 1,
        "player": {
            "playerId": 733234,
            "firstName": "cheng",
            "lastName": "w",
            "country": {
                "countryId": 13,
                "name": "China",
                "abbreviation": "CHN"
            }
        },
        "rounds": [
            {
                "roundNumber": 1,
                "startHole": 1
            },
            {
                "roundNumber": 2,
                "startHole": 10,
            },
            {
                "roundNumber": 3,
                "startHole": -1,
                "courseId": 950
            },
            {
                "roundNumber": 4,
                "startHole": -1,
                "courseId": 950
            }
        ]
    },
    {
        "place": 2,
        "player": {
            "playerId": 392990,
            "firstName": "Matt",
            "lastName": "Harmon",
            "country": {
                "countryId": 1,
                "name": "United States",
                "abbreviation": "USA"
            }
        },
        "rounds": [
            {
                "roundNumber": 1,
                "startHole": 1
            },
            {
                "roundNumber": 2,
                "startHole": 10,
            }
        ]
    }
]

I need to filter and create a new json using Lodash in the below format. I tried _.filter but always I am getting undefined error

{
    rounds: [
        [
            {
                player Name: "cheng",
                roundNumber: 1
                starthole: 1
            },
            {
                player Name: "math",
                roundNumber: 1
                starthole: 1
            }
        ],
        [
            {
                roundNumber: 2
                player Name: "cheng",
                starthole: 2
            },
            {
                roundNumber: 2
                player Name: "math",
                starthole: 2
            }
        ]
    ]
}

Is there any way to restructure the Json to new format using lodash and Javascript

Answer 1

You dont need filter. You need mapping as you are reformatting.

You can chain map and flatten. In Your case

let modifiedArray=_(YOURARRAYHERE).map(s=>{
    let x=_.map(s.rounds,a=>{
        return {
            roundNumber:a.roundNumber,
            startHole:a.startHole,
            playerName:s.player.firstName
        }
    });
    return x;
}).flatten().value();