[C#] Nullable Types - Value / Reference Types

[C#]  Nullable Types

Value Types  - int, float, double, structs, enums etc

Reference Types – Interface, Class, delegates, arrays etc

value types = non nullable

Reference = null ok

int i = 0 

=> i = null will generate compiler error

int? j = 0 

=> j is nullable int, so j=null is legal

data Types?

Nullable Types

NULL coalescing operator ??

NULL coalescing operator ?? null 일 경우의 초기값