Null Safety
Null Safety
Nullable types and Non-Null Types
Kotlin's type system is aimed at eliminating the danger of null references from code, also known as the The Billion Dollar Mistake.
One of the most common pitfalls in many programming languages, including Java is that of accessing a member of a null reference, resulting in a null reference exception. In Java this would be the equivalent of a NullPointerException or NPE for short.
Kotlin's type system is aimed to eliminate NullPointerException's from our code. The only possible causes of NPE's may be
- An explicit call to
throw NullPointerException() - Usage of the
!!operator that is described below - External Java code has caused it
- There's some
