1z0-809

1z0-809 practice questions, page 2 of 10, with answer review and explanations.

Question 6

Given: public class Counter { public static void main (String[ ] args) { int a = 10; int b = -1; assert (b >=1) : "Invalid Denominator"; int Ñ = a / b; System.out.println (c); } } What is the result of running the code with the ""ea option?

  1. -10
  2. 0
  3. An AssertionError is thrown.
  4. A compilation error occurs.

Question 7

Given: class Bird { public void fly () { System.out.print("Can fly"); } } class Penguin extends Bird { public void fly () { System.out.print("Cannot fly"); } } and the code fragment: class Birdie { public static void main (String [ ] args) { fly( ( ) -> new Bird ( )); fly (Penguin : : new); } /* line n1 */ } Which code fragment, when inserted at line n1, enables the Birdie class to compile?

  1. static void fly (Consumer<Bird> bird) { bird :: fly (); }
  2. static void fly (Consumer<? extends Bird> bird) { bird.accept( ) fly (); }
  3. static void fly (Supplier<Bird> bird) { bird.get( ) fly (); }
  4. static void fly (Supplier<? extends Bird> bird) { bird::fly(); }

Question 8

Given: 1. abstract class Shape { 2. Shape ( ) { System.out.println ("Shape"); } 3. protected void area ( ) { System.out.println ("Shape"); } 4. } 5. 6. class Square extends Shape { 7. int side; 8. Square int side { 9. /* insert code here */ 10. this.side = side; 11. } 12. public void area ( ) { System.out.println ("Square"); } 13. } 14. class Rectangle extends Square { 15. int len, br; 16. Rectangle (int x, int y) { 17. /* insert code here */ 18. len = x, br = y; 19. } 20. void area ( ) { System.out.println ("Rectangle"); } 21. } Which two modifications enable the code to compile? (Choose two.)

  1. At line 1, remove abstract
  2. At line 9, insert super ( );
  3. At line 12, remove public
  4. At line 17, insert super (x);
  5. At line 17, insert super (); super.side = x;
  6. At line 20, use public void area ( ) {

Question 9

Given: class Sum extends RecursiveAction { //line n1 static final int THRESHOLD_SIZE = 3; int stIndex, lstIndex; int [ ] data; public Sum (int [ ]data, int start, int end) { this.data = data; this stIndex = start; this. lstIndex = end; } protected void compute ( ) { int sum = 0; if (lstIndex "" stIndex <= THRESHOLD_SIZE) { for (int i = stIndex; i < lstIndex; i++) { sum += data [i]; } System.out.println(sum); } else { new Sum (data, stIndex + THRESHOLD_SIZE, lstIndex).fork( ); new Sum (data, stIndex, Math.min (lstIndex, stIndex + THRESHOLD_SIZE) ).compute (); } } } and the code fragment: ForkJoinPool fjPool = new ForkJoinPool ( ); int data [ ] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10} fjPool.invoke (new Sum (data, 0, data.length)); and given that the sum of all integers from 1 to 10 is 55. Which statement is true?

  1. The program prints several values that total 55.
  2. The program prints 55.
  3. A compilation error occurs at line n1.
  4. The program prints nothing.

Question 10

Given the content of Operator.java, EngineOperator.java, and Engine.java files: and the code fragment: What is the result?

  1. The Engine.java file fails to compile.
  2. The EngineOperator.java file fails to compile.
  3. The Operator.java file fails to compile.
  4. ON OFF