groupBy() function

将 Iterable/AsyncIterable 分割为集合,按通过 f 运行每个值的结果分组。

Signature:

declare function groupBy<A extends Key>(
  f: (a: A) => A,
  iterable: Iterable<A>,
): {
  [K in A]: K[];
};

Example

const given = [
  { category: "clothes", desc: "good" },
  { category: "pants", desc: "bad" },
  { category: "shoes", desc: "not bad" },
  { category: "shoes", desc: "great" },
  { category: "pants", desc: "good" },
];

groupBy((a) => a.category, given);
// {
//   clothes: [{ category: "clothes", desc: "good" }],
//   pants: [
//     { category: "pants", desc: "bad" },
//     { category: "pants", desc: "good" },
//   ],
//   shoes: [
//     { category: "shoes", desc: "not bad" },
//     { category: "shoes", desc: "great" },
//   ],
// };

Try It

Open Source Code