Download Oracle.1z0-809.PracticeTest.2019-01-29.52q.tqb
| Vendor: | Oracle |
| Exam Code: | 1z0-809 |
| Exam Name: | Java SE 8 Programmer II |
| Date: | Jan 29, 2019 |
| File Size: | 380 KB |
Demo Questions
Question 1
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?
- static void fly (Consumer<Bird> bird) {bird :: fly ();}
- static void fly (Consumer<? extends Bird> bird) {bird.accept( ) fly ();}
- static void fly (Supplier<Bird> bird) {bird.get( ) fly ();}
- static void fly (Supplier<? extends Bird> bird) {LOST
Correct answer: C
Question 2
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?
- At line 1, remove abstract
- At line 9, insert super ( );
- At line 12, remove public
- At line 17, insert super (x);
- At line 17, insert super (); super.side = x;
- At line 20, use public void area ( ) {
Correct answer: DF
Question 3
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?
- The program prints several values that total 55.
- The program prints 55.
- A compilation error occurs at line n1.
- The program prints several values whose sum exceeds 55.
Correct answer: A
Explanation:
