{
  "id": 1558341,
  "title": "How do I group an array of objects in JavaScript and sum a field?",
  "url": "https://urgent.news/2026/08/17/how-do-i-group-an-array-of-objects-in-javascript-and-sum-a-field",
  "topic": "tech",
  "section": "Tech",
  "published": "2026-08-17T20:37:34.000Z",
  "source": {
    "name": "Dev.to",
    "slug": "dev-to",
    "url": "https://dev.to/juli04guilar/how-do-i-group-an-array-of-objects-in-javascript-and-sum-a-field-54gi"
  },
  "original_language": "en",
  "account": "The article explains how to group a JavaScript array of objects and sum a specific field within each group. While modern tutorials recommend using native Object.groupBy(), this approach leaves developers writing additional reduce() loops to perform basic calculations like sum, average, or count on the grouped data.\n\nThe author introduces groupjs_by, a library that combines grouping and aggregation into a single, efficient operation. By using the groupBy() function from groupjs_by, you can easily sum a field (like revenue or amount) for each group derived from a specified key (such as status) in the input array of objects.\n\nThe article also provides an example of multi-key grouping, where you can specify an array of keys to group by simultaneously. This eliminates the need for nested loops and simplifies the code for creating chart-ready rows.\n\nTo use groupjs_by, simply install it via npm and then use the groupBy() function in your code. The library handles zero dependencies, offers a single-pass aggregation for large datasets, and automatically skips null, undefined, or non-numeric values to avoid NaN errors.\n\nThe full documentation, TypeScript examples, and performance benchmarks are available on the groupjs_by GitHub repository.",
  "summary": "import { groupBy } from ' groupjs_by ' ; const byStatus = groupBy ( orders , ' status ' ) . sum ( ' revenue ' , ' amount ' ) . count ( ' orders ' ) . toArray (); bash npm install groupjs_by Every modern article tells you to use native Object.groupBy(). The problem? It stops halfway. Native bucketing only splits your data into isolated arrays. It leaves you stuck writing messy reduce() loops just…",
  "key_points": [
    "Group a JavaScript array of objects using groupjsby's groupBy() function",
    "Sum a specific field (like revenue or amount) for each group based on a key (such as status)",
    "Install groupjsby via npm, handle zero dependencies, and skip null/undefined/non-numeric values"
  ],
  "editors_take": null,
  "illustration": null,
  "coverage": {
    "outlets": 1,
    "also_reported_by": []
  },
  "ai_generated": true,
  "disclaimer": "Summaries, key points and the editor’s take are written by software from other outlets’ reporting and may contain errors — always check the linked original."
}