groupBy

Groups an array based on a given criterion.

An iteratee function is provided to group items by the returned key. Each key is assigned as a property of the resulting object containing an array of grouped items.

Code

🔗 View source code

Benchmark

• hz: Operations per second
• mean: Average response time (ms)

Name	hz	mean	Performance
modern-kit/groupBy	6,982,132.03	0.0001	fastest
lodash/groupBy	4,223,901.69	0.0002	slowest

• modern-kit/groupBy
  • 1.65x faster than lodash/groupBy

Interface

typescript

function groupBy<T, K extends PropertyKey>(
  arr: T[] | readonly T[],
  iteratee: (item: T) => K
): Record<K, T[]>;

Usage

typescript

import { groupBy } from '@modern-kit/utils';

const items = [
  { category: 'fruit', name: 'apple' },
  { category: 'fruit', name: 'banana' },
  { category: 'vegetable', name: 'carrot' },
  { category: 'fruit', name: 'pear' },
  { category: 'vegetable', name: 'broccoli' },
];
const group = groupBy(items, (item) => item.category);
// {
//   fruit: [
//       { category: 'fruit', name: 'apple' },
//       { category: 'fruit', name: 'banana' },
//       { category: 'fruit', name: 'pear' },
//   ],
//   vegetable: [
//       { category: 'vegetable', name: 'carrot' },
//       { category: 'vegetable', name: 'broccoli' },
//   ],
// };

References

• Object.groupBy - MDN