Function countChars

countChars(str: string, char?: string): number
Counts characters in a string.
Parameters
- str: string
  The input string.
- Optionalchar: string
  Optional character to count.
Returns number
Number of characters or character occurrences.
Remarks
- If char is provided, only that character’s occurrences are counted.
- If char is omitted, the function counts the number of substrings returned by splitString (similar to a word count).
Example
```
countChars("banana");       // 6
countChars("banana", "a");  // 3
countChars("banana", "n");  // 2
```
- Defined in src/string/fn.ts:50