Short form for Java If statement returns NullPointerException when one of the returned objects is null [duplicate]

Answer 1

In the second case, the compiler can infer that the null must be a Long type. In the first case, it doesn't - and assumes that the expression returns a long. You can see that this is the case (i.e. fix it) like,

Long res = obj == null ? lNull : (Long) 10L;

which does not yield a NullPointerException.