Pushing onto an array within an array

Question

I hava an array vehicles which has an array within call Photos. For example:

[
    {
        "id": 251,
        "make": "Toyota",
        "model": "Land Cruiser ",
        "photos": [
            {
                "id": 7,
                "photoUrl": "https://.../1607009083.jpg",
            }
        ]
    },
    {
        "id": 264,
        "make": "Toyota",
        "model": "Land Cruiser  II ",
        "photos": [
            {
                "id": 9,
                "photoUrl": "https://.../1607005508.jpg",
            }
        ]
    }
]

If I upload a new photo I need to update the array. I know the vehicleId, photoId and photoUrl. Pushing onto the array I get an error:

this.vehicles[vehicleId].photos.push({id: photoId, photoUrl:  photoUrl})

Where am I going wrong?

What is `vehicleId`? Is it the index of the element or the `id` in the object? To access the second object's photos you can use `this.vehicles[1].photos` but not `this.vehicles[264].photos`. — Zsolt Meszaros, Dec 15 '20 at 10:37
Yes - shown as id in the root array. id within the photos array is the photoId — RGriffiths, Dec 15 '20 at 10:39
Still unclear to me. Assuming that outer array is `this.vehicles`, it has two elements: `this.vehicles[0]` and `this.vehicles[1]`. So again, if `vehicleId` is 251 or 264, this will not work (and please always post the error message) — , Dec 15 '20 at 10:43
Duplicate: [Find object by id in an array of JavaScript objects](https://stackoverflow.com/questions/7364150/find-object-by-id-in-an-array-of-javascript-objects) — , Dec 15 '20 at 10:44

wangdev87 · Accepted Answer · 2020-12-15T11:21:49.737

2

this.vehicles is the array and you should find index where the vehicleID is.

const index = this.vehicles.findIndex(v => v.id === vehicleId)
if (index !== -1) {
  this.vehicles[index].photos.push({id: photoId, photoUrl:  photoUrl})
} else {
  // No vehicle found with the vehicleId.
}

edited Dec 15 '20 at 11:21

answered Dec 15 '20 at 10:39

wangdev87

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1

Wouldn't it be easier to use `find()` instead of `findIndex()`? – Ivar Dec 15 '20 at 10:43
1

Please do not post answers to obvious duplicates. – Dec 15 '20 at 10:45

Pushing onto an array within an array

1 Answers1