Function splitString

splitString(str: string, val?: string | RegExp): string[]
Splits a string into an array of substrings using a given delimiter.
Parameters
- str: string
  The input string to split.
- val: string | RegExp = ...
  The delimiter (string or RegExp)
  
  Default
  whitespace /\s+/
Returns string[]
An array of substrings.
Remarks
- Defaults to splitting by whitespace using /\s+/.
- Does not trim leading/trailing spaces unless explicitly passed.
- Leading/trailing delimiters may produce empty strings.
- With /\s+/ specifically, consecutive whitespace is collapsed (no interior empty tokens).
Example
```
splitString("a b  c");      // ["a", "b", "c"]
splitString("a,b,c", ",");  // ["a", "b", "c"]
splitString("a1b2c3", /\d/); // ["a", "b", "c", ""]
```
- Defined in src/string/fn.ts:21