Function isAlphabeticUpper

isAlphabeticUpper(text?: null | string): boolean
Returns whether all the characters in the given text is uppercase alphabetic
Parameters
- Optionaltext: null | string
  the text to check
Returns boolean
whether all the characters in the given text is uppercase alphabetic
Author
David Hsing
Example
```
isAlphabeticUpper('ABC');    // true
isAlphabeticUpper('abc');    // false
isAlphabeticUpper('abc123');    // false
isAlphabeticUpper('123456');    // false
```