Friday task

All with friday!

We check knowledge and attention. Given Java code:

1. public class Foo { private static Foo instance = new Foo(); private static final int DELTA = 6; private static int BASE = 7; private int x; private Foo() { x = BASE + DELTA; } public static void main( String ... argv) { System. out .println(Foo.instance.x); } }
2. public class Foo { private static Foo instance = new Foo(); private static final int DELTA = 6; private static int BASE = 7; private int x; private Foo() { x = BASE + DELTA; } public static void main( String ... argv) { System. out .println(Foo.instance.x); } }
3. public class Foo { private static Foo instance = new Foo(); private static final int DELTA = 6; private static int BASE = 7; private int x; private Foo() { x = BASE + DELTA; } public static void main( String ... argv) { System. out .println(Foo.instance.x); } }
4. public class Foo { private static Foo instance = new Foo(); private static final int DELTA = 6; private static int BASE = 7; private int x; private Foo() { x = BASE + DELTA; } public static void main( String ... argv) { System. out .println(Foo.instance.x); } }
5. public class Foo { private static Foo instance = new Foo(); private static final int DELTA = 6; private static int BASE = 7; private int x; private Foo() { x = BASE + DELTA; } public static void main( String ... argv) { System. out .println(Foo.instance.x); } }
6. public class Foo { private static Foo instance = new Foo(); private static final int DELTA = 6; private static int BASE = 7; private int x; private Foo() { x = BASE + DELTA; } public static void main( String ... argv) { System. out .println(Foo.instance.x); } }
7. public class Foo { private static Foo instance = new Foo(); private static final int DELTA = 6; private static int BASE = 7; private int x; private Foo() { x = BASE + DELTA; } public static void main( String ... argv) { System. out .println(Foo.instance.x); } }
8. public class Foo { private static Foo instance = new Foo(); private static final int DELTA = 6; private static int BASE = 7; private int x; private Foo() { x = BASE + DELTA; } public static void main( String ... argv) { System. out .println(Foo.instance.x); } }
9. public class Foo { private static Foo instance = new Foo(); private static final int DELTA = 6; private static int BASE = 7; private int x; private Foo() { x = BASE + DELTA; } public static void main( String ... argv) { System. out .println(Foo.instance.x); } }
10. public class Foo { private static Foo instance = new Foo(); private static final int DELTA = 6; private static int BASE = 7; private int x; private Foo() { x = BASE + DELTA; } public static void main( String ... argv) { System. out .println(Foo.instance.x); } }
11. public class Foo { private static Foo instance = new Foo(); private static final int DELTA = 6; private static int BASE = 7; private int x; private Foo() { x = BASE + DELTA; } public static void main( String ... argv) { System. out .println(Foo.instance.x); } }
12. public class Foo { private static Foo instance = new Foo(); private static final int DELTA = 6; private static int BASE = 7; private int x; private Foo() { x = BASE + DELTA; } public static void main( String ... argv) { System. out .println(Foo.instance.x); } }

')
Attention question! What will be displayed? And most importantly - why?

UPD Caution - the correct answer is already in the comments. Please conduct a test in other PLs and provide the results in the comments.