ts-group-by
This package allows you to group an array by one or more levels while maintaining type safety.
How to install
npm install ts-group-byBasic usage:
import { groupBy } from "ts-group-by";
const data = [
{ agency: "Agency A", patient: "Carol baskin", gender: "F" },
{ agency: "Agency A", patient: "Carol baskin", gender: "F" },
{ agency: "Agency A", patient: "Esther Friedman", gender: "M" },
{ agency: "Agency A", patient: "Zaritskaia Raia", gender: "M" },
{ agency: "Agency B", patient: "Judy Gottesman", gender: "F" },
];
const groupedByAgency = groupBy(data, "agency");
// : Map<string, { agency: string; patient: string; gender: string; }[]>
// = Map {
// 'Agency A' => [
// { agency: 'Agency A', patient: 'Carol baskin', gender: 'F' },
// { agency: 'Agency A', patient: 'Carol baskin', gender: 'F' },
// { agency: 'Agency A', patient: 'Esther Friedman', gender: 'M' },
// { agency: 'Agency A', patient: 'Zaritskaia Raia', gender: 'M' }
// ],
// 'Agency B' => [
// { agency: 'Agency B', patient: 'Judy Gottesman', gender: 'F' }
// ]
// }Group by two levels:
const groupedByAgencyAndGender = groupBy(data, "agency", "gender");
// : Map<string, Map<string, { agency: string; patient: string; gender: string; }[]>>
// = Map {
// 'Agency A' => Map {
// 'F' => [
// { agency: 'Agency A', patient: 'Carol baskin', gender: 'F' },
// { agency: 'Agency A', patient: 'Carol baskin', gender: 'F' }
// ],
// 'M' => [
// { agency: 'Agency A', patient: 'Esther Friedman', gender: 'M' },
// { agency: 'Agency A', patient: 'Zaritskaia Raia', gender: 'M' }
// ]
// }
// 'Agency B' => Map {
// 'F' => [
// { agency: 'Agency B', patient: 'Judy Gottesman', gender: 'F' }
// ]
// }
// }