Function isUndefined

isUndefined(value): value is undefined
Checks if value is undefined.
Parameters
- value: any
  The value to check.
Returns value is undefined
Returns true if value is undefined, else false.
Since
5.6.0
Example
```
isUndefined(void 0)
// => true

isUndefined(null)
// => false
```
- Defined in build/repo/src/isUndefined.ts:18