Please choose all the answers that apply. Select 2 options.

		A class can extend one class and implements many interfaces
		An interface can extend many interfaces
		A class can extend one class and many interfaces
		A class can implement one class and many interfaces
		An interface can extend many classes and interfaces
		An interface can implement many classes and interfaces
		An interface can implement many interfaces

4 points

QUESTION 10

Consider the following class: public class A { public int timesTwo(int x) { return x + x; } } Which of the following classes inherits from A but replaces the timesTwo() method with a new implementation?

		class B extends A { public int timesTwo (int x) { return x * 2; } }
		public class A extends B { public int timesTwo (int x) { return x * 2; } }
		public class B extends A { public float timesTwo (float x) { return x * 2.0F; } }
		public class B extends A { }

4 points

QUESTION 11

What is the output of compiling and running the following program? class Category { Category() { System.out.println("Constructor of Category"); } } class SubCategory extends Category { SubCategory() { System.out.println("Constructor of SubCategory"); } } class SubSubCategory extends SubCategory { SubSubCategory() { System.out.println("Constructor of SubSubCategory"); } } public class Tester { public static void main(String[] args) { new SubSubCategory(); } }

		None of the mentioned
		Constructor of SubSubCategory
		Constructor of Category Constructor of SubCategory Constructor of SubSubCategory
		Constructor of SubSubCategory Constructor of SubCategory Constructor of Category

5 points

QUESTION 12

The following program fails to compile, where could possibly be the compilation error(s)? Select 2 options. class Creature { } class Bird extends Creature { } class Falcon extends Bird { } public class Tester { public static void main(String[] args) { Creature c1 = new Creature(); Creature c2 = new Bird(); Bird b1 = (Bird) c1; // Line 1 Bird b2 = (Falcon) c2; // Line 2 Bird b3 = c2; // Line 3 Bird b4 = new Falcon(); // Line 4 Bird b5 = (Bird) new Creature(); // Line 5 Falcon f1 = b4; // Line 6 } }

		Line 3
		Line 4
		Line 5
		Line 6
		Line 1
		Line 2

4 points

QUESTION 13

What keyword or keywords are used to indicate that a class inherits from another class?

		inherits
		is a
		extends
		implements

4 points

QUESTION 14

Which statement(s), inserted independently at the insertion point in the main function, will compile and run successfully? Select 2 options. class Creature { String getName() { return "Creature"; } } class Bird extends Creature { String getName() { return "Bird"; } } class Falcon extends Bird { String getName() { return "Falcon"; } } public class Tester { public static Bird getIt(Creature c) { System.out.println(c.getName()); return (Bird) c; } public static void main(String[] args) { // insert code here } }

		getIt(new Bird());
		getIt(new Falcon());
		getIt(new Creature());
		getIt(new Object());

4 points

QUESTION 15

What is the result of compiling and running the following code? class Base { public Base() { System.out.println("Base"); } } public class Derived extends Base { public Derived() { this("JavaChamp"); System.out.println("Derived"); } public Derived(String s) { System.out.println(s); } public static void main(String[] args) { new Derived(); } }

		JavaChamp Base Derived
		JavaChamp Derived Base
		The code will not compile
		Base JavaChamp Derived
		JavaChamp Derived