Function toInteger

toInteger(
    source?: null | string | number,
    defaultValue?: number,
    floorValue?: boolean,
): undefined | number
Returns an integer value from the given source
Parameters
- Optionalsource: null | string | number
  the source value to inspect
- OptionaldefaultValue: number
  the default value if the source cannot be converted
- floorValue: boolean = true
  Whether to floor the source, otherwise to ceil
Returns undefined | number
an integer value from the given source
Author
David Hsing
Example
```
toInteger('1');    // 1
toInteger(1.3);    // 1
toInteger('1.7', undefined, false);    // 2
```