如何按键名对对象数组进行分组？

Question

I have an array of objects and I want to group them by object's key names. I have tried to do this with Array.reduce() , but the result is not good since it's grouped by values. Here is the example of an array I have and example of what I've tried so far

 const rawData = [ { "EmailCampaignEvents.campaignRef": "my-first-campaign", "EmailCampaignEvents.customerRef": "Customer/0", "EmailCampaignEvents.emailRef": "Customer/0", "EmailCampaignEvents.eventType": "initial_open", "EmailCampaignEvents.occurredAt": "2021-02-25T14:03:04.000" }, { "EmailCampaignEvents.campaignRef": "my-second-campaign", "EmailCampaignEvents.customerRef": "Customer/123", "EmailCampaignEvents.emailRef": "Customer/123", "EmailCampaignEvents.eventType": "delivery", "EmailCampaignEvents.occurredAt": "2021-03-25T14:03:04.000" }, { "Events.occurredAt": "2020-11-11T15:44:07.000", "Events.relatedEntityRefFlat": "Customer/6711684", "Events.type": "as.commerce.transaction.completed" } ]; result = rawData.reduce(function (r, a) { r[a["EmailCampaignEvents.eventType"]] = r[a["EmailCampaignEvents.eventType"]] || []; r[a["EmailCampaignEvents.eventType"]].push(a); r[a["Events.type"]] = r[a["Events.type"]] || []; r[a["Events.type"]].push(a); return r; }, Object.create(null)); console.log(result);

And the result I try to achieve is something like this

{ 
  "EmailCampaignEvents.eventType": [
    {
      "EmailCampaignEvents.campaignRef": "my-first-campaign",
      "EmailCampaignEvents.customerRef": "Customer/0",
      "EmailCampaignEvents.emailRef": "Customer/0",
      "EmailCampaignEvents.eventType": "initial_open",
      "EmailCampaignEvents.occurredAt": "2021-02-25T14:03:04.000"
    },
    {
      "EmailCampaignEvents.campaignRef": "my-second-campaign",
      "EmailCampaignEvents.customerRef": "Customer/123",
      "EmailCampaignEvents.emailRef": "Customer/123",
      "EmailCampaignEvents.eventType": "delivery",
      "EmailCampaignEvents.occurredAt": "2021-03-25T14:03:04.000"
    },
  ],
  "Events.type": [
    {
      "Events.occurredAt": "2020-11-11T15:44:07.000",
      "Events.relatedEntityRefFlat": "Customer/6711684",
      "Events.type": "as.commerce.transaction.completed"
    }
  ]
}

Does anyone know how can I achieve this, but not using lodash or any other library? Any example will be appreciated!

Answer 1

You could check if the 'Events.type' exists in the object, then take this string as key for the group, otherwise take 'EmailCampaignEvents.eventType' as key.

 const rawData = [{ "EmailCampaignEvents.campaignRef": "my-first-campaign", "EmailCampaignEvents.customerRef": "Customer/0", "EmailCampaignEvents.emailRef": "Customer/0", "EmailCampaignEvents.eventType": "initial_open", "EmailCampaignEvents.occurredAt": "2021-02-25T14:03:04.000" }, { "EmailCampaignEvents.campaignRef": "my-second-campaign", "EmailCampaignEvents.customerRef": "Customer/123", "EmailCampaignEvents.emailRef": "Customer/123", "EmailCampaignEvents.eventType": "delivery", "EmailCampaignEvents.occurredAt": "2021-03-25T14:03:04.000" }, { "Events.occurredAt": "2020-11-11T15:44:07.000", "Events.relatedEntityRefFlat": "Customer/6711684", "Events.type": "as.commerce.transaction.completed" }], result = rawData.reduce((r, o) => { const key = 'Events.type' in o? 'Events.type': 'EmailCampaignEvents.eventType'; (r[key]??= []).push(o); return r; }, Object.create(null)); console.log(result);

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