Kotlin Null Safety

Introduction

Kotlin's null safety system eliminates NullPointerExceptions at compile time by distinguishing between nullable and non-nullable types in the type system. This approach makes null handling explicit and forces developers to consciously handle potential null values.

Unlike Java where any reference can be null, Kotlin requires explicit declaration of nullability with the ? operator. The compiler enforces null checks before dereferencing nullable values, preventing the vast majority of null-related crashes that plague Java applications.

This skill covers nullable types, safe call operators, smart casts, nullability in generic types, and patterns for designing null-safe APIs while maintaining code clarity.

Nullable Types