The compiler interprets null as a null reference to an Integer, applies the autoboxing/unboxing rules for the conditional operator (as described in the Java Language Specification, 15.25), and moves happily on. This will generate a NullPointerException at run time, which you can confirm by trying it.
No, == between Integer, Long etc will check for reference equality – i.e. Integer x = …; Integer y = …; System.out.println(x == y); this will check whether x and y refer to the same object rather than equal objects. So Integer x = new Integer(10); Integer y = new Integer(10); System.out.println(x == y); is … Read more
Streams In Java 8+ you can make a stream of your int array. Call either Arrays.stream or IntStream.of. Call IntStream#boxed to use boxing conversion from int primitive to Integer objects. Collect into a list using Stream.collect( Collectors.toList() ). Or more simply in Java 16+, call Stream#toList(). Example: int[] ints = {1,2,3}; List<Integer> list = Arrays.stream(ints).boxed().collect(Collectors.toList()); … Read more