Function countFrequencies

countFrequencies(str: string): Record<string, number>
Builds a frequency map of characters in a string.
Parameters
- str: string
  The input string.
Returns Record<string, number>
A mapping of each character to its frequency.
Remarks
- Returns an object where keys are characters and values are counts.
- Case-sensitive by default.
Example
```
countFrequencies("banana");
// { b: 1, a: 3, n: 2 }

countFrequencies("");
// {}
```
- Defined in src/string/fn.ts:126