1z0-809 Sample Questions & Answers

Given:

public class Counter {

public static void main (String[ ] args) {

int a = 10;

int b = -1;

assert (b )=1) : “Invalid Denominator';

int = a / b;

System.out.println (c);

}

}

What is the result of running the code with the -ea option?

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?

Given:

1. abstract class Shape {

2. Shape ( ) { System.out.println (“Shape'); }

3. protected void area ( ) { System.out.println (“Shape'); }

4. }

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.)

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 (IstIndex - 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?

Given the content of Operator.java, EngineOperator.java, and Engine.java files:

What is the result?

Given the code fragment:

Stream(List(String)) iStr= Stream.of (

Arrays.asList (“1', “John'),

Arrays.asList (“2', null));

Stream((String) nInSt = iStr.flatMapToInt ((x) -) x.stream ());

nInSt.forEach (System.out :: print);

What is the result?

Given the code fragment:

Path file = Paths.get (“courses.txt');

// line n1

Assume the courses.txt is accessible.

Which code fragment can be inserted at line n1 to enable the code to print the content of the courses.txt file?

Given the code fragment:

public void recDelete (String dirName) throws IOException {

File [ ] listOfFiles = new File (dirName) .listFiles();

if (listOfFiles ! = nulllistOfFiles.length )0) {

for (File aFile : listOfFiles) {

if (aFile.isDirectory ()) {

recDelete (aFile.getAbsolutePath ());

} else {

if (aFile.getName ().endsWith (“.class'))

Oracle 1z0-809 Exam aFile.delete ();

}

}

}

}

Assume that Projects contains subdirectories that contain .class files and is passed as an argument to the recDelete () method when it is invoked.

What is the result?

Given the code fragments:

4. void doStuff() throws ArithmeticException, NumberFormatException, Exception {

5. if (Math.random() )-1 throw new Exception (“Try again');

6. }

and

24. try {

25. doStuff ( ):

26. } catch (ArithmeticException | NumberFormatException | Exception e) {

27. System.out.println (e.getMessage()); }

28. catch (Exception e) {

29. System.out.println (e.getMessage()); }

}

Which modification enables the code to print Try again?

Given the definition of the Country class:

public class country {

public enum Continent {ASIA, EUROPE}

String name;

Continent region;

public Country (String na, Continent reg) {

name = na, region = reg;

}

public String getName () {return name;}

public Continent getRegion () {return region;}

}

and the code fragment:

List(Country) couList = Arrays.asList (

new Country (“Japan', Country.

Continent.

ASIA),

new Country (“Italy', Country.

Continent.

EUROPE),

new Country (“Germany', Country.

Continent.

EUROPE));

Map(Country.

Continent, List(String)) regionNames = couList.stream ()

.collect(Collectors.groupingBy (Country ::getRegion,

Collectors.mapping(Country::getName, Collectors.toList()))));

System.out.println(regionNames);

What is the output?