1z0-809 sample questions

Question 1

Given the definition of the Vehicle class:

Class Vehicle {

int distance;

Vehicle (int x) {

this distance = x;

}

public void increSpeed(int time) {

int timeTravel = time; //line n1

//line n3

class Car {

int value = 0;

public void speed () {

value = distance /timeTravel;//line n2

System.out.println (“Velocity with new speed'+value+'kmph');

}

speed();//line n3

}

and this code fragment:

Vehicle v = new Vehicle (100);

v.increSpeed(60);

What is the result?

Accepted Answer

Velocity with new speed 1 kmph

Answer

A compilation error occurs at line n1.

Answer

A compilation error occurs at line n2.

Answer

A compilation error occurs at line n3.

Question 2

Given:

IntStream stream = IntStream.of (1,2,3);

IntFunction(Integer) inFu= x -) y -) x*y;//line n1

IntStream newStream = stream.map(inFu.apply(10));//line n2 newStream.forEach(System.out::print);

Which modification enables the code fragment to compile?

Accepted Answer

Replace line n1 with:

IntFunction(IntUnaryOperator) inFu = x -) y -) x*y;

Answer

Replace line n1 with:

IntFunction(UnaryOperator) inFu = x -) y -) x*y;

Answer

Replace line n1 with:

BiFunction(IntUnaryOperator) inFu = x -) y -) x*y;

Answer

Replace line n2 with:

IntStream newStream = stream.map(inFu.applyAsInt (10));

Question 3

Given the code fragment:

List(Integer) values = Arrays.asList (1, 2, 3);

values.stream ()

.map(n -) n*2)//line n1

.peek(System.out::print)//line n2

.count();

What is the result?

Accepted Answer

246

Answer

The code produces no output.

Answer

A compilation error occurs at line n1.

Answer

A compilation error occurs at line n2.

Question 4

Given the code fragment:

public class Foo {

public static void main (String [ ] args) {

Map(Integer, String) unsortMap = new HashMap( ) ( );

unsortMap.put (10, “z');

unsortMap.put (5, “b');

unsortMap.put (1, “d');

unsortMap.put (7, “e');

unsortMap.put (50, “j');

Map(Integer, String) treeMap = new TreeMap (Integer, String) (new

Comparator(Integer) ( ) {

@Override public int compare (Integer o1, Integer o2) {return o2.compareTo

(o1); } } );

treeMap.putAll (unsortMap);

for (Map.

Entry(Integer, String) entry : treeMap.entrySet () ) {

System.out.print (entry.getValue () + “ “);

}

What is the result?

Accepted Answer

j z e b d

Answer

A compilation error occurs.

Answer

d b e z j

Answer

z b d e j

Question 5

Which two reasons should you use interfaces instead of abstract classes? (Choose two.)

Accepted Answer

You expect that unrelated classes would implement your interfaces.

Accepted Answer

You want to take advantage of multiple inheritance of type.

Answer

You expect that classes that implement your interfaces have many common methods or fields, or require access modifiers other than public.

Answer

You want to share code among several closely related classes.

Answer

You want to declare non-static on non-final fields.

Question 6

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?

Accepted Answer

An AssertionError is thrown.

Answer

-10

Answer

0

Answer

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?

Accepted Answer

static void fly (Supplier(Bird) bird) {

bird.get( ) fly ();

}

Answer

static void fly (Consumer(Bird) bird) {

bird :: fly ();

}

Answer

static void fly (Consumer(? extends Bird) bird) {

bird.accept( ) fly ();

}

Answer

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.)

Accepted Answer

At line 17, insert super (x);

Accepted Answer

At line 20, use public void area ( ) {

Answer

At line 1, remove abstract

Answer

At line 9, insert super ( );

Answer

At line 12, remove public

Answer

At line 17, insert super (); super.side = x;

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 (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?

Accepted Answer

The program prints several values that total 55.

Answer

The program prints 55.

Answer

A compilation error occurs at line n1.

Answer

The program prints nothing.

Question 10

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

What is the result?

Accepted Answer

The Engine.java file fails to compile.

Answer

The EngineOperator.java file fails to compile.

Answer

The Operator.java file fails to compile.

Answer

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Free 1z0-809 sample questions

Given: IntStream stream = IntStream.of (1,2,3); IntFunction(Integer) inFu= x -) y -) x*y;//line n1 IntStream newStream = stream.map(inFu.apply(10));//line n2 newStream.forEach(System.out::print); Which modification enables the code fragment to compile?

Given the code fragment: List(Integer) values = Arrays.asList (1, 2, 3); values.stream () .map(n -) n*2)//line n1 .peek(System.out::print)//line n2 .count(); What is the result?

Which two reasons should you use interfaces instead of abstract classes? (Choose two.)

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

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