Nullable types and the ternary operator: why is `? 10 : null` forbidden? [duplicate]

by

The compiler first tries to evaluate the right-hand expression:

GetBoolValue() ? 10 : null

The 10 is an int literal (not int?) and null is, well, null. There’s no implicit conversion between those two hence the error message.

If you change the right-hand expression to one of the following then it compiles because there is an implicit conversion between int? and null (#1) and between int and int? (#2, #3).

GetBoolValue() ? (int?)10 : null    // #1
GetBoolValue() ? 10 : (int?)null    // #2
GetBoolValue() ? 10 : default(int?) // #3

More Related Contents:

  1. Why doesn’t the conditional operator correctly allow the use of “null” for assignment to nullable types? [duplicate]
  2. Conditional operator assignment with Nullable types?
  3. How to check if an object is nullable?
  4. What is the difference between Nullable.HasValue or Nullable != null?
  5. Nullable type issue with ?: Conditional Operator
  6. Nullable type is not a nullable type?
  7. What does “DateTime?” mean in C#?
  8. How to parse a string into a nullable int
  9. What are lifted operators?
  10. Why is this code invalid in C#?
  11. In C# why can’t a conditional operator implicitly cast to a nullable type
  12. Why GetType returns System.Int32 instead of Nullable? [duplicate]
  13. Invalid cast from ‘System.Int32’ to ‘System.Nullable`1[[System.Int32, mscorlib]]
  14. Optional return in C#.Net
  15. Where in memory are nullable types stored?
  16. How is the boxing/unboxing behavior of Nullable possible?
  17. Type result with conditional operator in C#
  18. Are nullable types reference types?
  19. Boxing / Unboxing Nullable Types – Why this implementation?
  20. how are nullable types implemented under the hood in .net?
  21. How do I restart my C# WinForm Application?
  22. Why should I implement ICloneable in c#?
  23. SQLite Database Locked exception
  24. Determine if a type is static
  25. Create web service proxy in Visual Studio from a WSDL file
  26. EF5 Getting this error message: Model compatibility cannot be checked because the database does not contain model metadata
  27. What do ref, val and out mean on method parameters?
  28. Async and Await with For Loop [duplicate]
  29. Understanding Covariance and Contravariance in C# 4.0
  30. caching the result from a [n async] factory method iff it doesn’t throw

Leave a Comment