Function groupBy

groupBy<Item, Key>(grouper: Unary<Item, Key>): (<Iterable>(iterable: Iterable) => ReducerOutput<Iterable, Readonly<Record<Key, ReadOnlyArray<Item>>>>)
Groups values of an iterable or asynchronous iterable in an object based on the output of the grouper function.

Example
```
const groupByType = groupBy((value: number) => number % 2 === 0 ? "even" : "odd");
groupByType([1, 2, 3, 4, 5]); // { even: [2, 4], odd: [1, 3, 5] }
```
Returns
Object with grouped values.
Type Parameters
- Item
- Key extends PropertyKey
Parameters
- grouper: Unary<Item, Key>
  
  Grouper function.
Returns (<Iterable>(iterable: Iterable) => ReducerOutput<Iterable, Readonly<Record<Key, ReadOnlyArray<Item>>>>)
- - <Iterable>(iterable: Iterable): ReducerOutput<Iterable, Readonly<Record<Key, ReadOnlyArray<Item>>>>
  - Type Parameters
    - Iterable extends AsynchronousIterable<Item>
    Parameters
    - iterable: Iterable
    Returns ReducerOutput<Iterable, Readonly<Record<Key, ReadOnlyArray<Item>>>>
- Defined in groupBy.ts:22