What is the difference between `*val* x: String? =...

# getting-started

[Alexander Suraphel]

What is the difference between
*val* x: String? = y *as* String? and
*val* x: String? = y *as*? String ?

[Richard Gomez]

With as, if y cannot be safely cast to String it will throw an exception. With as?, it will simply return null.

[CLOVIS]

*safely cast to String?

as String?
Crashes for everything that isn't a String or null,

as? String
Accepts any value, returns a String if it is one, null otherwise.

[CLOVIS]

(both allow null)

[CLOVIS]

If you don't want null, the solution is to use as String, which will crash for any non-String value (even null)

[Alexander Suraphel]

Thanks guys! I understand the distinction now.