Function emptyAsUndefined

emptyAsUndefined<E>(array?: null | E[]): undefined | null | (undefined | E)[]
Returns a array that replaced the empty element to undefined from the given array
Type Parameters
- E
Parameters
- Optionalarray: null | E[]
  The arrays to inspect
Returns undefined | null | (undefined | E)[]
a array that replaced the empty element to undefined from the given array
Author
David Hsing
Example
```
emptyAsUndefined(['foo', 'bar']);    // ['foo', 'bar']
emptyAsUndefined(['foo', '']);    // ['foo', undefined]
emptyAsUndefined(['', 'bar']);    // [undefined, 'bar']
```