Java SE 17 Developer practice questions

1. Question 1 of 25

   Given the code fragment:

   

   and

   

   Which is true?

   • AThe program prints t1 : 1 : t2 : 1: t1 : 2 : t2 : 2 : in random order.
   • BThe program prints t1 : 1 : t2 : 1: t1 : 2 : t2 : 2 :
   • CThe program prints t1 : 1 : t2 : 1: t1 : 1 : t2 : 1 : indefinitely.
   • DThe program prints an exception.

   Show answer

   Correct answer: A

   How others answered

   • A100%

   Explanation

   // Result: // t2 : 1 : t2 : 2 : t1 : 1 : t1 : 2 : // t1 : 1 : t2 : 1 : t2 : 2 : t1 : 2 : // t1 : 1 : t2 : 1 : t1 : 2 : t2 : 2 : // t1 : 1 : t2 : 1 : t1 : 2 : t2 : 2 :

   Adapted from community discussion by james2033 · 2024-02-11 · 2 community upvotes. Third-party contribution; reviewed by our quality filter, not independently verified.

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   Question 1 discussion

   These are quality-filtered excerpts from third-party community discussion. They can be useful reasoning signals, but they are not official answers and have not been independently verified by 1Z0-829 or CertExamHQ.

   1. N

      Naoufal18

      2024-12-23

      Selected A1 upvote

      n the given code, two threads (t1 and t2) are running concurrently and printing the values of x and xObj, respectively. The execution order of the threads can vary due to their concurrent nature. Here's the breakdown: Thread 1 (t1) is operating on the volatile int x variable. It increments x from 1 to 2 as part of the while (t.x < 3) loop. Thread 2 (t2) is operating on the AtomicInteger xObj. It increments xObj from 1 to 2 and then to 3 as part of the while (t.xObj.get() < 3) loop.

   2. A

      ASPushkin

      2025-03-24

      Selected A1 upvote

      Only one thread t1 has access to Test.x. Only one thread t2 has access to Test.xObj. Monitor (implicit synchronization) of Instance class Test is not used. There is no thread interference at all here. Even if we remove keyword volatile and exchange optimistic locking AtomicInteger variable regular Integer the thread execution order is generally unpredictable because of not absolute contract with underlying OS in order to perform threads scheduling.

   3. J

      james2033

      2024-02-11

      Selected A2 upvotes

      // Result: // t2 : 1 : t2 : 2 : t1 : 1 : t1 : 2 : // t1 : 1 : t2 : 1 : t2 : 2 : t1 : 2 : // t1 : 1 : t2 : 1 : t1 : 2 : t2 : 2 : // t1 : 1 : t2 : 1 : t1 : 2 : t2 : 2 :

   4. X

      xplorerpj

      2024-06-15

      1 upvote

      A is the correct answer. The below gets printed in random Order. t2:1: t2:2: t1:1: t1:2:

2. Question 2 of 25

   Given:

   

   What is the result?

   • ACompilation fails.
   • Bthere
   • Chello
   • DA NumberFormatException is thrown.

   Show answer

   Correct answer: C

   How others answered

   • C100%

   Explanation

   package q10; public class Main { void print(int i) { System.out.println("hello"); } void print(long j) { System.out.println("there"); } public static void main(String[] args) { new Main().print(0b1101_1010); } } // Result: // hello

   Adapted from community discussion by james2033 · 2024-02-15 · 4 community upvotes. Third-party contribution; reviewed by our quality filter, not independently verified.

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   Question 2 discussion

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   1. J

      james2033

      2024-02-15

      Selected C4 upvotes

      package q10; public class Main { void print(int i) { System.out.println("hello"); } void print(long j) { System.out.println("there"); } public static void main(String[] args) { new Main().print(0b1101_1010); } } // Result: // hello

3. Question 3 of 25

   Given the code fragment:

   

   Which set of class definitions compiles?

   • Ainterface Story extends SInt {} interface Art extends SInt {}
   • Bpublic interface Story extends SInt {} public interface Art extends SInt {}
   • Csealed interface Story extends SInt {} non-sealed class Art implements SInt {}
   • Dnon-sealed interface Story extends SInt {} non-sealed interface Art extends SInt {}
   • Enon-sealed interface Story extends SInt {} class Art implements SInt {}

   Show answer

   Correct answer: D

   How others answered

   • D100%

   Explanation

   The right option is D. non-sealed interface Story extends SInt {} non-sealed interface Art extends SInt {}, because the class in option E require an modifier

   Adapted from community discussion by Tojose · 2024-01-11 · 3 community upvotes. Third-party contribution; reviewed by our quality filter, not independently verified.

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   Question 3 discussion

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   1. S

      supersquax

      2024-01-25

      4 upvotes

      Right answer is D. E is missing "sealed", "non-sealed" or "final" modifier.

   2. T

      Tojose

      2024-01-11

      3 upvotes

      The right option is D. non-sealed interface Story extends SInt {} non-sealed interface Art extends SInt {}, because the class in option E require an modifier

   3. M

      minhdev

      2024-05-05

      2 upvotes

      D is correct, Sealed interface allows sealed, non-sealed interface extends it.

   4. F

      filledapril

      2024-07-11

      1 upvote

      if option E is like: E. non-sealed interface Story extends SInt {} non-sealed class Art implements SInt {} , in this case should select the E

4. Question 4 of 25

   Given the code fragment:

   

   What is the result?

   • AABBCDE // the order of elements is unpredictable
   • BABCDE
   • CABCDE // the order of elements is unpredictable
   • DADEABCB // the order of elements is unpredictable

   Show answer

   Correct answer: C

   How others answered

   • C100%

   Explanation

   package q13; import java.util.stream.Stream; public class Q13 { public static void main(String[] args) { Stream s1 = Stream.of("A", "B", "C", "B"); Stream s2 = Stream.of("A", "D", "E"); Stream.concat(s1, s2).parallel().distinct().forEach(element -> System.out.print(element)); } } // Result: // CEDBA // CEDAB // CEDBA

   Adapted from community discussion by james2033 · 2024-08-15 · 4 community upvotes. Third-party contribution; reviewed by our quality filter, not independently verified.

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   Question 4 discussion

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   1. J

      james2033

      2024-08-15

      Selected C4 upvotes

      package q13; import java.util.stream.Stream; public class Q13 { public static void main(String[] args) { Stream s1 = Stream.of("A", "B", "C", "B"); Stream s2 = Stream.of("A", "D", "E"); Stream.concat(s1, s2).parallel().distinct().forEach(element -> System.out.print(element)); } } // Result: // CEDBA // CEDAB // CEDBA

5. Question 5 of 25

   Given the content of the in.txt file: 0123456789 and the code fragment:

   

   What is the content of the out.txt file?

   • A012345678
   • B01234567801234
   • C01234567
   • D0123456789
   • E012345678901234
   • F0123456789234567

   Show answer

   Correct answer: F

   How others answered

   • F100%

   Explanation

   package q17; import java.io.FileNotFoundException; import java.io.FileReader; import java.io.FileWriter; import java.io.IOException; public class Q17 { public static void main(String[] args) throws Exception { char[] buffer = new char[8]; int count = 0; try (FileReader in = new FileReader("D:\\in.txt"); FileWriter out = new FileWriter("D:\\out.txt")) { while ((count = in.read(buffer)) != -1) { out.write(buffer); } } // catch (FileNotFoundException e) { // throw new RuntimeException(e); // } catch (IOException e) { // throw new RuntimeException(e); // } } } // Result: // 0123456789234567

   Adapted from community discussion by james2033 · 2024-02-17 · 3 community upvotes. Third-party contribution; reviewed by our quality filter, not independently verified.

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   Question 5 discussion

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   1. J

      james2033

      2024-02-17

      Selected F3 upvotes

      package q17; import java.io.FileNotFoundException; import java.io.FileReader; import java.io.FileWriter; import java.io.IOException; public class Q17 { public static void main(String[] args) throws Exception { char[] buffer = new char[8]; int count = 0; try (FileReader in = new FileReader("D:\\in.txt"); FileWriter out = new FileWriter("D:\\out.txt")) { while ((count = in.read(buffer)) != -1) { out.write(buffer); } } // catch (FileNotFoundException e) { // throw new RuntimeException(e); // } catch (IOException e) { // throw new RuntimeException(e); // } } } // Result: // 0123456789234567

   2. J

      j_jain

      2024-03-01

      2 upvotes

      Correct answer is F Buffer already contains 01234567 and we have 89 left so next time it will replace 0 with 8 and 1 with 9. As there is no data left so it will write 89234567.

   3. 4

      4d8d7fe

      2024-07-11

      2 upvotes

      In the first iteration de char array is 01234567(only can contain 8 size). But in the second iteration is 89234567

   4. S

      supersquax

      2024-01-31

      1 upvote

      Correct option is F, because the buffer is of size 8. Therefore, it can only read 8 characters at a time. First 8 digits in F are correct and the entire thing is of length 16. Although the first 8 digits in B and E are correct, the entire length doesn't add it. Doesn't make sense that the buffer first reads 8 chars, then 6 more in B or 7 more in E.

6. Question 6 of 25

   Which statement is true?

   • AIllegalStateException is thrown if a thread in waiting state is moved back to runnable.
   • BA thread in waiting state consumes CPU cycles.
   • CAfter the timed wait expires, the waited thread moves to the terminated state.
   • DA thread in waiting state must handle InterruptedException.

   Show answer

   Correct answer: D

   How others answered

   • D100%

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   1. A

      ASPushkin

      2025-03-28

      Selected D1 upvote

      A. IllegalStateException is thrown if a thread in waiting state is moved back to runnable. false it moves back to runnable as a result of notify(), notifyAll() or time elapsed or finish the thread (join()) B thread in waiting state consumes CPU cycles. false A thread is inactive when in the blocked or waiting state. When in these states, the thread does not consume any CPU cycles. D. A thread in waiting state must handle InterrupedException. true public void run() In inheritance method must not throw new or checked exception So any checked exception has to be handled inside Object.join Object.wait Thread.sleep all of them throw InterruptedException

7. Question 7 of 25

   Given the code fragment: List<Integer> listOfNumbers = List.of(1, 2, 3, 4, 5, 6, 7, 8, 9, 10); Which code fragment returns different values?

   • Aint sum = listOfNumbers.stream().reduce(0, Integer::sum) + 5;
   • Bint sum = listOfNumbers.parallelStream().reduce(0, Integer::sum) + 5 ;
   • Cint sum = listOfNumbers.parallelStream().reduce((m, n) -> m + n).orElse(5) + 5;
   • Dint sum = listOfNumbers.parallelStream().reduce(5, Integer::sum);
   • Eint sum = listOfNumbers.stream().reduce(5, (a, b) -> a+ b);

   Show answer

   Correct answer: D

   How others answered

   • D100%

   Explanation

   // D. int sum = listOfNumbers.parallelStream().reduce(5, Integer::sum); // (1 + 5) + (2 + 5) + (3 + 5) + (4 + 5) + (5 + 5) + (6 + 5) + (7 + 5) + (8 + 5) + (9 + 5) + (10 + 5) = 105 System.out.println(">>> sum = " + sum); // >>> sum = 105 A, B, C, E return sum = 60.

   Adapted from community discussion by james2033 · 2024-02-22 · 2 community upvotes. Third-party contribution; reviewed by our quality filter, not independently verified.

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   Question 7 discussion

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   1. J

      james2033

      2024-02-22

      Selected D2 upvotes

      // D. int sum = listOfNumbers.parallelStream().reduce(5, Integer::sum); // (1 + 5) + (2 + 5) + (3 + 5) + (4 + 5) + (5 + 5) + (6 + 5) + (7 + 5) + (8 + 5) + (9 + 5) + (10 + 5) = 105 System.out.println(">>> sum = " + sum); // >>> sum = 105 A, B, C, E return sum = 60.

   2. S

      SrinivasJasti

      2024-12-29

      Selected D1 upvote

      Non-determinism in parallel streams, the elements are partitioned into smaller sub-streams, and the reduction is performed on each sub-stream independently. it's possible that the 5 (initial value provided to reduce()) is added to some elements before they are added to others.

8. Question 8 of 25

   Select 2

   Given the code fragment:

   

   Which two statements at Line n1 independently enable you to print 1250? (Choose two.)

   • AInteger res = 250 + Integer.parseInt(s);
   • BInteger res = 250 + Integer.valueOf(s);
   • CInteger res = 250 + s2;
   • DInteger res = 250; res =+ s2;
   • EInteger res = 250 + s;
   • FInteger res = 250 + Integer(s2);

   Show answer

   Correct answer: C, D

   How others answered

   • CD100%

   Explanation

   package q25; public class Q25 { public static void main(String[] args) { String s = "10_00"; Integer s2 = 10_00; // Line n1 // A. // Integer res = 250 + Integer.parseInt(s); // parseInt exception. // B. // Integer res = 250 + Integer.valueOf(s); // parseInt exception. // C. // Integer res = 250 + s2; // at the end, result = 1250 . // D. Integer res = 250; res += s2; // At then end, result = 1250 . // E. // Integer res = 250 + s; // Syntax error. // F. // Integer res = 250 + Integer(s2); // Syntax error. System.out.println(res); } }

   Adapted from community discussion by james2033 · 2024-02-22 · 2 community upvotes. Third-party contribution; reviewed by our quality filter, not independently verified.

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   Question 8 discussion

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   1. J

      james2033

      2024-02-22

      Selected C, D2 upvotes

      package q25; public class Q25 { public static void main(String[] args) { String s = "10_00"; Integer s2 = 10_00; // Line n1 // A. // Integer res = 250 + Integer.parseInt(s); // parseInt exception. // B. // Integer res = 250 + Integer.valueOf(s); // parseInt exception. // C. // Integer res = 250 + s2; // at the end, result = 1250 . // D. Integer res = 250; res += s2; // At then end, result = 1250 . // E. // Integer res = 250 + s; // Syntax error. // F. // Integer res = 250 + Integer(s2); // Syntax error. System.out.println(res); } }

   2. S

      supersquax

      2024-01-31

      3 upvotes

      Should be C and D, but D should have "+=" instead of "=+". I've tried all the alternatives in an online compiler and these are the only ones that work. A and B would work if "s" were "1000", but parseInt() and valueOf() arent able to handle the underscore in "10_00". E is just plain wrong cuz s is a string and cant be automatically cast to an int. F is wrong cuz "Integer()" casting doesn't exist. One would instead use valueOf() to cast.

   3. S

      SrinivasJasti

      2024-12-29

      Selected C, D1 upvote

      thousand separator in numeric literals is accepted from java7 10_00 means 1000

   4. X

      xplorerpj

      2024-06-19

      1 upvote

      CD but there's an error with the display of Answer option D D. Integer res = 250; res =+ s2; This will only return 1000 in result because there's no operator like =+ The correct choice of answer would be as below (for D), D. Integer res = 250; res += s2;

9. Question 9 of 25

   Assume you have an automatic module from the module path display-ascii-0.2.jar. Which name is given to the automatic module based on the given JAR file?

   • Adisplay-ascii-0
   • Bdisplay-ascii
   • Cdisplay.ascii
   • Ddisplay-ascii-0.2

   Show answer

   Correct answer: C

   How others answered

   • C100%

   Explanation

   The correct answer is C. After removal of .jar, the version number '0.2', and trailing special character '-' The remaining special characters in between letters is replaced with a dot(.) Thus the automatic name will be 'display.ascii'

   Adapted from community discussion by zuluitai · 2024-06-19 · 3 community upvotes. Third-party contribution; reviewed by our quality filter, not independently verified.

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   1. Z

      zuluitai

      2024-06-19

      3 upvotes

      The correct answer is C. After removal of .jar, the version number '0.2', and trailing special character '-' The remaining special characters in between letters is replaced with a dot(.) Thus the automatic name will be 'display.ascii'

   2. T

      Tojose

      2024-01-11

      2 upvotes

      the right answer is C. display.ascii becasuse java converts any special characters in in the name to dots

10. Question 10 of 25

    Which statement is true about migration?

    • AEvery module is moved to the module path in a bottom-up migration.
    • BEvery module is moved to the module path in a top-down migration.
    • CUnnamed modules are automatic modules in a top-down migration.
    • DThe required modules migrate before the modules that depend on them in a top-down migration.

    Show answer

    Correct answer: B

    How others answered

    • B100%

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    Question 10 discussion

    These are quality-filtered excerpts from third-party community discussion. They can be useful reasoning signals, but they are not official answers and have not been independently verified by 1Z0-829 or CertExamHQ.

    1. T

       Tojose

       2024-01-11

       3 upvotes

       I think the correct answer is B. Every module is moved to the module path in a top-down migration.

11. Question 11 of 25

    Daylight Saving Time (DST) is the practice of advancing clocks at the start of spring by one hour and adjusting them backward by one hour in autumn. Considering that in 2021, DST in Chicago (Illinois) ended on November 7th at 2 AM, and given the fragment:

    

    What is the output?

    • Atrue true
    • Bfalse true
    • Ctrue false
    • Dfalse false

    Show answer

    Correct answer: C

    How others answered

    • C100%

    Explanation

    package q03; import java.time.LocalDate; import java.time.LocalTime; import java.time.ZoneId; import java.time.ZonedDateTime; public class Q03 { public static void main(String[] args) { ZoneId zoneId = ZoneId.of("America/Chicago"); ZonedDateTime zdt = ZonedDateTime.of( LocalDate.of(2021, 11, 7), LocalTime.of(1, 30), zoneId ); ZonedDateTime anHourLater = zdt.plusHours(1); System.out.println(zdt.getHour() == anHourLater.getHour()); System.out.print(zdt.getOffset().equals(anHourLater.getOffset())); } } // Result: // true // false

    Adapted from community discussion by james2033 · 2024-02-11 · 2 community upvotes. Third-party contribution; reviewed by our quality filter, not independently verified.

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    Question 11 discussion

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    1. J

       james2033

       2024-02-11

       Selected C2 upvotes

       package q03; import java.time.LocalDate; import java.time.LocalTime; import java.time.ZoneId; import java.time.ZonedDateTime; public class Q03 { public static void main(String[] args) { ZoneId zoneId = ZoneId.of("America/Chicago"); ZonedDateTime zdt = ZonedDateTime.of( LocalDate.of(2021, 11, 7), LocalTime.of(1, 30), zoneId ); ZonedDateTime anHourLater = zdt.plusHours(1); System.out.println(zdt.getHour() == anHourLater.getHour()); System.out.print(zdt.getOffset().equals(anHourLater.getOffset())); } } // Result: // true // false

    2. A

       ASPushkin

       2025-03-30

       Selected C1 upvote

       The current date is November 7th time is 1:30 am November 7th 2am is a DST winter time ZonedDateTime zdt = ZonedDateTime.of( LocalDate.of(2021, 11, 7), LocalTime.of(1, 30), zoneId ); ZonedDateTime anHourLater = zdt.plusHours(1); means transition to DST winter zone and setting clocks back to one hour

    3. X

       xplorerpj

       2024-06-15

       1 upvote

       C is the correct answer //zdt : 2021-11-07T01:30-05:00[America/Chicago] //anHourLater : 2021-11-07T01:30-06:00[America/Chicago] //zdt.Offset : -05:00 //anHourLater.Offset: -06:00

12. Question 12 of 25

    Assuming that the data.txt file exists and has the following content: text1 text2 text3 Given the code fragment:

    

    What is the result?

    • Atext1- text2- text3- text3
    • Btext1-text2-text3 A java.lang.IndexOutOfBoundsException is thrown.
    • Ctext1-text2-text3 text1 text2 text3
    • Dtext1-text2-text3 text3

    Show answer

    Correct answer: B

    How others answered

    • B100%

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    1. S

       SrinivasJasti

       2024-12-30

       Selected B1 upvote

       the indices used when accessing lines from a file using Files.readAllLines() are zero-based. This means: The first line of the file has an index of 0. The second line has an index of 1. The third line has an index of 2, and so on.

    2. S

       supersquax

       2024-01-31

       2 upvotes

       B correct. Java uses 0 indexing so we only have items 0 (text1), 1 (text2), and 2 (text3). Index 3 outa bounds.

    3. X

       xplorerpj

       2024-06-25

       1 upvote

       Answer is B (text1-text2-text3), when input file has text in 3 different lines, in input file. text1 text2 text3 And Index out of bounds occur since there are only 2 items.

13. Question 13 of 25

    Given:

    

    Which action enables the code to compile?

    • AReplace 2 with static String name;
    • BReplace 7 with public static void display(String design) {
    • CReplace 3 with private static void display() {
    • DReplace 15 with Item.display("Flower");

    Show answer

    Correct answer: A

    How others answered

    • A100%

    Explanation

    Correct answer is A, tested in online compiler. static methods cannot access instance variable unless they are static. That is to say: - either the "name" variable must be made static so that it can be accessed by the display() method on line 3 - or the display() method on line 3 must be made non-static (remove the static keyword) so that it can access the "name" variable Only alternative that achieves one of these two is A. Note that despite this change, i1.display("Flower") will still call the display() method on line 7. Non-static methods are allowed to access static instance variable regardless. In this case, since both "this.name" and "name" are null, "this.name += name;" will simply do "null += null;" and the result will be "nullnull".

    Adapted from community discussion by supersquax · 2024-07-31 · 5 community upvotes. Third-party contribution; reviewed by our quality filter, not independently verified.

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    1. S

       supersquax

       2024-07-31

       5 upvotes

       Correct answer is A, tested in online compiler. static methods cannot access instance variable unless they are static. That is to say: - either the "name" variable must be made static so that it can be accessed by the display() method on line 3 - or the display() method on line 3 must be made non-static (remove the static keyword) so that it can access the "name" variable Only alternative that achieves one of these two is A. Note that despite this change, i1.display("Flower") will still call the display() method on line 7. Non-static methods are allowed to access static instance variable regardless. In this case, since both "this.name" and "name" are null, "this.name += name;" will simply do "null += null;" and the result will be "nullnull".

    2. S

       SrinivasJasti

       2024-12-30

       Selected A1 upvote

       The name field is an instance variable (non-static), but you are trying to access it directly from the static method display().So add static to the variable

14. Question 14 of 25

    Given:

    

    and the code fragment:

    

    What is the result?

    • AMarketing
    • BMarketing - Finance - Technical
    • CMarketing - UnDefined
    • DUnDefined

    Show answer

    Correct answer: A

    How others answered

    • A100%

    Explanation

    package q33; import java.util.Arrays; public class Q33 { public static void main(String[] args) { Arrays.stream(Desig.values()).dropWhile(s -> s.equals(Desig.CMO)); switch (Desig.valueOf("CMO")) { case CEO -> System.out.println("Executive"); case CMO -> System.out.println("Marketing"); case CFO -> System.out.println("Finance"); case CTO -> System.out.println("Technical"); default -> System.out.println("UnDefined"); } } } // Result: // Marketing

    Adapted from community discussion by james2033 · 2024-02-22 · 3 community upvotes. Third-party contribution; reviewed by our quality filter, not independently verified.

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    1. J

       james2033

       2024-02-22

       Selected A3 upvotes

       package q33; import java.util.Arrays; public class Q33 { public static void main(String[] args) { Arrays.stream(Desig.values()).dropWhile(s -> s.equals(Desig.CMO)); switch (Desig.valueOf("CMO")) { case CEO -> System.out.println("Executive"); case CMO -> System.out.println("Marketing"); case CFO -> System.out.println("Finance"); case CTO -> System.out.println("Technical"); default -> System.out.println("UnDefined"); } } } // Result: // Marketing

    2. S

       SrinivasJasti

       2024-12-30

       Selected A1 upvote

       The result of the dropWhile operation is unused because the method call is not assigned to a variable or consumed.

15. Question 15 of 25

    Select 2

    Given:

    

    Which two method invocations execute? (Choose two.)

    • Anew MyC().m2();
    • BIFace.m4();
    • CIFace myClassObj = new MyC(); myClassObj.m3();
    • DIFace myClassObj = new MyC(); myClassObj.m4();
    • EIFace.m3();
    • FIFace.m2();

    Show answer

    Correct answer: A, E

    How others answered

    • AE100%

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    1. S

       SrinivasJasti

       2024-12-30

       Selected A, E1 upvote

       B. IFace.m4(); // private method not accesible C. IFace myClassObj = new MyC(); myClassObj.m3(); //non static access of static method not possible D. IFace myClassObj = new MyC(); myClassObj.m4(); // private access not possible IFace.m2(); // static access non static method not possible

16. Question 16 of 25

    Select 2

    Given the directory structure:

    

    Given the definition of the Doc class:

    

    Which two are valid definitions of the WordDoc class? (Choose two.)

    • Apackage p1.p2; public non-sealed class WordDoc extends Doc { }
    • Bpackage p1; public final class WordDoc extends Doc {}
    • Cpackage p1; non-sealed abstract class WordDoc extends Doc {}
    • Dpackage p1.p2: public sealed class WordDoc extends Doc { }
    • Epackage p1; public class WordDoc extends Doc {}
    • Fpackage p1; public non-sealed class WordDoc extends Doc {}

    Show answer

    Correct answer: B, F

    How others answered

    • BF100%

    Explanation

    A wrong cuz "package p1.p2" doesnt make sense B correct C wrong cuz no access modifier is more restrictive than public and not allowed. D wrong cuz when using "sealed", one must also use "permits" E wrong cuz missing "sealed", "non-sealed", or "final" F correct.

    Adapted from community discussion by supersquax · 2024-07-31 · 2 community upvotes. Third-party contribution; reviewed by our quality filter, not independently verified.

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    1. S

       supersquax

       2024-07-31

       2 upvotes

       A wrong cuz "package p1.p2" doesnt make sense B correct C wrong cuz no access modifier is more restrictive than public and not allowed. D wrong cuz when using "sealed", one must also use "permits" E wrong cuz missing "sealed", "non-sealed", or "final" F correct.

    2. S

       SrinivasJasti

       2024-12-30

       Selected B, F1 upvote

       A and D ---> incorrect WordDoc is not in the same package as Doc.C ---->incorrect, Does not have public or final, E---> incorrect,WordDoc must declare itself as final, sealed, or non-sealed when extending a sealed class

17. Question 17 of 25

    Select 2

    Given:

    

    and

    

    Which two should the module-info file include for it to represent the service provider interface? (Choose two.)

    • Aexports com.transport.vehicle.cars;
    • Bprovides com.transport.vehicle.cars.impl.CarImpl to com.transport.vehicle.cars.Car;
    • Crequires com.transport.vehicle.cars.Car;
    • Dexports com.transport.vehicle.cars.Car;
    • Erequires com.transport.vehicle.cars;
    • Fexports com.transport.vehicle;
    • Gprovides com.transport.vehicle.cars.Car with com.transport.vehicle.cars.impl.CarImpl;

    Show answer

    Correct answer: A, G

    How others answered

    • AG100%

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    1. S

       SrinivasJasti

       2024-12-30

       Selected A, G1 upvote

       A --> You need to export the package where the service interface (Car) is located, G---> This line specifies that CarImpl provides the service Car in correct order

18. Question 18 of 25

    Given the Product class:

    

    and the Shop class:

    

    What is the result?

    • ACompilation fails.
    • BCookie 0.0 2.99
    • CCookie 2.99 2.99
    • DCookie 3.99 2.99
    • EAn exception is produced at runtime.
    • FCookie 0.0 0.0

    Show answer

    Correct answer: B

    How others answered

    • B100%

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    1. S

       SrinivasJasti

       2024-12-30

       Selected B1 upvote

       The Java Serialization API is designed to recognize only a private readObject method for deserialization purposes. Since it is public ,loses its special status in the serialization process.The transient fields are not restored to their intended values threfore price remains 0.0 leading to Cookie 0.0 2.99

    2. L

       Langton

       2024-11-09

       2 upvotes

       Answer is B because for readObject() method to be called it has to be difined as private which is not the case here

19. Question 19 of 25

    Given the code fragments:

    

    and:

    

    Which action prints Wagon : 200?

    • AAt line n1, implement the java.io.AutoCloseable interface.
    • BAt line n3, replace Car with LuxuryCar.
    • CAt line n1, implement the java.io.Serializable interface.
    • DAt line n3, replace readObject() with readLine().
    • EAt line n2, in the main method signature, add throws IOException, ClassNotFoundException.
    • FAt line n2, in the main method signature, add throws IOException, ClassCastException.

    Show answer

    Correct answer: E

    How others answered

    • E100%

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    1. T

       Tojose

       2024-01-11

       8 upvotes

       the right option is E. At line n2, in the main method signature, add throws IOException, ClassNotFoundException.

    2. S

       SrinivasJasti

       2024-12-30

       Selected E1 upvote

       IOException (for file-related issues during serialization/deserialization). ClassNotFoundException (thrown by ObjectInputStream.readObject() if the class cannot be found during deserialization).

20. Question 20 of 25

    Given: Captions.properties file: user = UserName Captions_en.properties file: user = User name (EN) Captions_US.properties file: message = User name (US) Captions_en_US.properties file: message = User name (EN - US) and the code fragment:

    

    What is the result?

    • AUser name (EN - US)
    • BThe program throws a MissingResourceException.
    • CUserName
    • DUser name (EN)
    • EUser name (US)

    Show answer

    Correct answer: D

    How others answered

    • D100%

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    1. S

       SrinivasJasti

       2024-12-30

       Selected D1 upvote

       Captions_en_US.properties will be matched when currentLocale was "en_US" since it is just "en" it matches Captions_en.properties ---> User name (EN)

21. Question 21 of 25

    Given:

    

    and the code fragment:

    

    Which statement is true?

    • AThe program throws ClassCastException.
    • BThe program fails to compile.
    • CThe program throws StockException.
    • DThe program throws OutofStockException.

    Show answer

    Correct answer: D

    How others answered

    • D100%

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    1. Z

       zuluitai

       2024-06-20

       Selected D1 upvote

       D is correct. // Exception in thread "main" q45.OutofStockException: Raised.

    2. X

       xplorerpj

       2024-06-23

       1 upvote

       D is correct Exception in thread "main" com.examtopics.OutOfStockException: Raised

22. Question 22 of 25

    Given:

    

    Which two modifications enable the code to print Open Close?

    • AReplace line n1 with: class Folder extends Closeable {
    • BReplace line n1 with: class Folder implements AutoCloseable {
    • CAt line n2, insert:
    • DReplace line n1 with: class Folder extends Exception {
    • EAt line n2, insert:

    Show answer

    Correct answer: B

    How others answered

    • B100%

    Explanation

    B and C correct. A is wrong cuz both Closeable and AutoCloseable are "interfaces", not classes. Therefore, the "implements" keyword must be used. D wrong. the fact that it is "final" and doesnt throw anything is fine, but it is missing the "public" keyword. trying to compile without "public" gives this error: "attempting to assign weaker access privileges; was public"

    Adapted from community discussion by supersquax · 2024-01-31 · 3 community upvotes. Third-party contribution; reviewed by our quality filter, not independently verified.

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    1. S

       supersquax

       2024-01-31

       3 upvotes

       B and C correct. A is wrong cuz both Closeable and AutoCloseable are "interfaces", not classes. Therefore, the "implements" keyword must be used. D wrong. the fact that it is "final" and doesnt throw anything is fine, but it is missing the "public" keyword. trying to compile without "public" gives this error: "attempting to assign weaker access privileges; was public"

    2. S

       SrinivasJasti

       2024-12-30

       Selected B1 upvote

       B & C are correct ---->The two key modifications that enable the code to print "Open Close" are: Implement AutoCloseable in the Folder class. Override the close() method in the Folder class.

23. Question 23 of 25

    Given the code fragment:

    

    Which action sorts the book list?

    • AAt Line n2, replace books.sort() with books.stream().sort().
    • BAt Line n1, convert books type to mutable ArrayList type.
    • CAt Line n2, replace compareTo() with compare().
    • DAt Line n1, convert books type to mutable array type.

    Show answer

    Correct answer: B

    How others answered

    • B100%

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    1. S

       SrinivasJasti

       2024-12-30

       Selected B1 upvote

       Since List.of() creates an immutable list, changing it to a mutable list -->. List books = new ArrayList<>(List.of( new Book("A1", "T1"), new Book("A2", "T2"), new Book("A1", "T2") ));

24. Question 24 of 25

    Given the course table:

    

    Given the code fragment:

    

    What is the result?

    • A2
    • Btrue
    • Cfalse
    • D1

    Show answer

    Correct answer: A

    How others answered

    • A100%

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    1. S

       SrinivasJasti

       2024-12-30

       Selected A1 upvote

       A (2): This would be the correct result because the query will affect two rows, even if the data does not change and executeUpdate() returns the number of affected rows not true or false

25. Question 25 of 25

    Given the code fragment:

    

    Which action enables the code to compile?

    • AReplace record with void.
    • BReplace record with class.
    • CRemove the regNo initialization statement.
    • DMake the regNo variable public.
    • EMake the regNo variable static.

    Show answer

    Correct answer: E

    How others answered

    • E100%

    Explanation

    package q06; record Product(int pNumber, String pName) { // int regNo = 100; static int regNo = 100; public int getRegNumber() { return regNo; } } public class App { public static void main(String[] args) { Product p1 = new Product(1111, "Ink Bottle"); } }

    Adapted from community discussion by james2033 · 2024-02-11 · 4 community upvotes. Third-party contribution; reviewed by our quality filter, not independently verified.

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    1. J

       james2033

       2024-02-11

       Selected E4 upvotes

       package q06; record Product(int pNumber, String pName) { // int regNo = 100; static int regNo = 100; public int getRegNumber() { return regNo; } } public class App { public static void main(String[] args) { Product p1 = new Product(1111, "Ink Bottle"); } }

    2. A

       ASPushkin

       2025-04-06

       Selected E1 upvote

       answer: E "It is a compile-time error for the body of a record declaration to contain a non-static field declaration" jls17 8.10

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