Function count

count<Iter, V, T>(iter, key?): AnyItResult<Iter, Map<T, number>>
Counts the number of occurrences of each value in an iterable.
```
it.count('hello') == it.m.map([['h', 1], ['e', 1], ['l', 2], ['o', 1]])
```
Use the second parameter to get the key used to count.
```
const input = [{x: 'a'}, {x: 'b'}]
it.count(input, obj => obj.x) == it.m.map([[true, 2], [false, 0]])
```
Type Parameters
- Iter extends AnyIt<unknown>
- V extends unknown
- T = V
Parameters
- iter: Iter
  The iterable to count the occurrences from.
- Optional key: ValFunc<V, T>
  The function used to determine the group key. Defaults to the identity function.
Returns AnyItResult<Iter, Map<T, number>>
- A Map containing the count of each value.
- Defined in src/operators/count.ts:33