Java Foundation_9

_____automatically converts a primitive to the corresponding wrapper classes when needed if the generic type is specified in the declaration.

• unboxing

• Autoboxing

• Boxing

• AutoConversion

The syntax for introducing a generic is to declare a _____parameter in angle brackets

• actual

• unformal

• formal

• real

Method/field in a class (that is not a superclass) in a different package can access ___

• If that member is private

• If that member has default (package private) access?

• If that member is protected?

• If that member is public?

Member in a superclass in a different package can access ___

• If that member is private

• If that member has default (package private) access?

• If that member is protected?

• If that member is public?

For overriding, the overridden method should follow that:

• The access modifier must be the same or more accessible.

• The return type must be the same or a more restrictive type, also known as covariant return types.

• If any checked exceptions are thrown, only the same exceptions or subclasses of those exceptions are allowed to be thrown.

• The methods must not be static.

An abstract class may contain any number of methods including ____

• 0

• 1

• atleast 1

• minimum 2

To which lines in the following code could you independently add static and/or final without introducing a compiler error?
1: abstract class Cat {

2: String name = "The Cat";

3: void clean() { }

4: }

5: class Lion extends Cat {

6: void clean() { }

7: }

• 1 & 5

• 1 & 3

• 3

• 1

• 2

How many different ways can you think of to write imports that will make this code compile?

public class ListHelper {

public List copyAndSortList(List original) {

List list = new ArrayList (original);

sort(list);

return list;

} }

• import static java.util.Collections.sort;and
  import static java.util.Collections.*;

• import static java.util.Collections.sort;

  or

  import static java.util.Collections.*;

• import static java.util.Collections.sort.*;

  and

  import static java.util.Collections.*;

• import static java.util.Collections.sort.*;

  and

  import static java.util.Collections.*.sort;

In a instanceof B, the expression returns true _____,

• if the reference to which B points is an instance of class a and b

• if the reference to which B points is an instance of class A

• if the reference to which A points is an instance of class b

• if the reference to which a points is an instance of class B

You have three classes with which to work:

class HeavyAnimal { }

class Hippo extends HeavyAnimal { }

class Elephant extends HeavyAnimal { }

You see that Hippo is a subclass of HeavyAnimal but not Elephant. Remember that the exam starts with line numbers other than 1 when showing a code snippet. This is to tell you that you can assume the correct code comes before what you see. You can assume any missing code is correct and all imports are present.

12: HeavyAnimal hippo = new Hippo();

13: boolean b1 = hippo instanceof Hippo;

14: boolean b2 = hippo instanceof HeavyAnimal;

15: boolean b3 = hippo instanceof Elephant;

• 13 gives true

  14 gives true

  15 gives false

• 13 gives false

  14 gives true

  15 gives false

• 13 gives true

  14 gives false

  15 gives false

• 13 gives true

  14 gives true

  15 gives true