Clearly the machine code the JIT compiler can generate for the first case is much more efficient. One rule that really helps there is that an object can only be unboxed to a variable that has the same type as the boxed value. That allows the JIT compiler to generate very efficient code, no value … Read more
The compiler replaces null comparisons with a call to HasValue, so there is no real difference. Just do whichever is more readable/makes more sense to you and your colleagues.
There are two types of nullable – Nullable<T> and reference-type. Jon has corrected me that it is hard to get type if boxed, but you can with generics: – so how about below. This is actually testing type T, but using the obj parameter purely for generic type inference (to make it easy to call) … Read more
The problem occurs because the conditional operator doesn’t look at how the value is used (assigned in this case) to determine the type of the expression — just the true/false values. In this case, you have a null and an Int32, and the type can not be determined (there are real reasons it can’t just … Read more
First, you should read all about Null Safety in Kotlin which covers the cases thoroughly. In Kotlin, you cannot access a nullable value without being sure it is not null (Checking for null in conditions), or asserting that it is surely not null using the !! sure operator, accessing it with a ?. Safe Call, … Read more
Of course, people will do what they want. But we did have a clear intention when adding this feature, and it was not to be a general purpose Maybe type, as much as many people would have liked us to do so. Our intention was to provide a limited mechanism for library method return types … Read more
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 … Read more