Free Oracle 1Z0-809 Exam Questions

Given code of Test.java file: 

1. package com.udayan.ocp;

2.  

3. import java.util.ArrayDeque;

4. import java.util.Deque;

5.  

6. public class Test {

7.     public static void main(String[] args) {

8.         Deque deque = new ArrayDeque<>();

9.         deque.push(new Boolean("abc"));

10.         deque.push(new Boolean("tRuE"));

11.         deque.push(new Boolean("FALSE"));

12.         deque.push(true);

13.         System.out.println(deque.pop() + ":" + deque.peek() + ":" + deque.size());

14.     }

15. }

What will be the result of compiling and executing Test class?

Below is the code of Test.java file:

1. package com.udayan.ocp;

2.  

3. class Outer {

4.     static class Inner {

5.         static void greetings(String s) {

6.             System.out.println(s);

7.         }

8.     }

9. }

10.  

11. public class Test {

12.     public static void main(String[] args) {

13.         /*INSERT*/

14.     }

15. }

Which of the following 2 options can replace /*INSERT*/ such that there on executing class Test, output is: HELLO!?

Given code of Test.java file: 

1. package com.udayan.ocp;

2.  

3. public class Test {

4.     private static String msg = "Hello";

5.  

6.     private static String changeMsg(String m) {

7.         msg = m;

8.         return null;

9.     }

10.  

11.     public static void main(String[] args) {

12.         if(args.length == 0) {

13.             assert false : changeMsg("Bye");

14.         }

15.         System.out.println(msg);

16.     }

17. }

What will be the result of executing Test class with below command? 

java -ea com.udayan.ocp.Test

Given code of Test.java file: 

1. package com.udayan.ocp;

2.  

3. import java.util.Arrays;

4. import java.util.Comparator;

5. import java.util.List;

6.  

7. class Person {

8.     private String firstName;

9.     private String lastName;

10.  

11.     public Person(String firstName, String lastName) {

12.         this.firstName = firstName;

13.         this.lastName = lastName;

14.     }

15.  

16.     public String getFirstName() {

17.         return firstName;

18.     }

19.  

20.     public String getLastName() {

21.         return lastName;

22.     }

23.  

24.     public String toString() {

25.         return "{" + firstName + ", " + lastName + "}";

26.     }

27. }

28.  

29. public class Test {

30.     public static void main(String[] args) {

31.         List list = Arrays.asList(

32.                 new Person("Tom", "Riddle"),

33.                 new Person("Tom", "Hanks"),

34.                 new Person("Yusuf", "Pathan"));

35.         list.stream().sorted(Comparator.comparing(Person::getFirstName).reversed()

36.                 .thenComparing(Person::getLastName)).forEach(System.out::println);

37.     }

38. }

What will be the result of compiling and executing Test class?

Given code of Test.java file:

1. package com.udayan.ocp;

2.  

3. interface Printer1 {

4.     default void print() {

5.         System.out.println("Printer1");

6.     }

7. }

8.  

9. class Printer2 {

10.     public void print() {

11.         System.out.println("Printer2");

12.     }

13. }

14.  

15. class Printer extends Printer2 implements Printer1 {

16.  

17. }

18.  

19. public class Test {

20.     public static void main(String[] args) {

21.         Printer printer = new Printer();

22.         printer.print();

23.     }

24. }

What will be the result of compiling and executing Test class?