Oracle 1Z0-813 Online Practice Questions and Exam Preparation

Oracle 1Z0-813 Online Questions & Answers

• Question 11:

  Given the code fragments:

  

  and

  

  Which modification enables the code to print Try again?

  A. Replace line 27 with: throw e;
  B. Replace line 26 with: } catch (ArithmeticException | NumberFormatException e) {
  C. Replace line 26 with: } catch (Exception | ArithmeticException | NumberFormatException e) {
  D. Comment the lines 28, 29, and 30.
  B. Replace line 26 with: } catch (ArithmeticException | NumberFormatException e) {

  ---

  The problem with line 26 is that alternatives in a multi-catch statements cannot be related by subclassing. Alternative ArithmeticException is a subclass of alternative Exception.

• Question 12:

  Given the code fragment:

  

  Which two code fragments, when inserted at line n1 independently, result in the output PEEK: Unix? (Choose two.)

  A. .noneMatch();
  B. .anyMatch();
  C. .allMatch();
  D. .findFirst();
  E. .findAny();
  D. .findFirst();
  E. .findAny();

  ---

  The findXXX methods, FinFirst() and findAny, take no arguments and return an Optional object with the result, or an empty Optional if nothing is found.

  Incorrect Answers:

  A, B, C: XXXMatch methods. Take a Predicate and return a boolean if an element in the stream returns true by applying the Predicate.

  Reference: http://eherrera.net/ocpj8-notes/05-java-stream-api

• Question 13:

  Given the code fragment:

  

  Which code fragment, when inserted at line n1, enables the code to print the count of string elements whose length is greater than three?

  A. listVal.stream().filter(x -> x.length() > 3).count()
  B. listVal.stream().map(x -> x.length() > 3).count()
  C. listVal.stream().peek(x -> x.length() > 3).count().get()
  D. listVal.stream().filter(x -> x.length() > 3).mapToInt(x -> x).count()
  A. listVal.stream().filter(x -> x.length() > 3).count()

  ---

  Gives the correct output of 2. Incorrect Answers:

  B: Output is 4.

  C, D: Does not compile.

• Question 14:

  Given the code fragment: Which two changes, taken together, enable the use of this class in a try-with-resources statement? (Choose two.)

  

  A. public class CustomRecourse extends AutoCloseable {
  B. public class CustomResource implements Closeable {
  C. public class CustomResource extends Closeable implements AutoCloseable {
  D. Add a method: public void autoClose() throws IOException { }
  E. Add a method: public boolean close() throws IOException { }
  F. Add a method: public void close() throws IOException { }
  B. public class CustomResource implements Closeable {
  F. Add a method: public void close() throws IOException { }

  ---

  A Closeable is a source or destination of data that can be closed. The close method is invoked to release resources that the object is holding (such as open files). It closes this stream and releases any system resources associated with it. If the stream is already closed then invoking this method has no effect. It throws an IOException - if an I/O error occurs.

  Reference: https://docs.oracle.com/javase/7/docs/api/java/io/Closeable.html

• Question 15:

  Given:

  

  What is the result?

  A. class java,lang.ArrayIndexOutOfBoundsException
  B. null
  C. class java.lang.NullPointerException
  D. class java.lang.Exception
  E. Compilation fails
  B. null

• Question 16:

  Given code fragments:

  

  and

  

  What is the result?

  A. [Dog, Cat, Mouse]
  B. DogCatMouse
  C. null
  D. A compilation error occurs.
  D. A compilation error occurs.

  ---

  A compilation error: Uncompilable source code - Erroneous sym type: java.util.List.forEach at line: t.getList().forEach(Test::printValues);

• Question 17:

  Given the code fragment:

  

  Which code fragment, when inserted at line n1, enables the code to print [500,1000]?

  A. Function funIntf = n -> n * 5;
  B. Consumer funIntf = n -> n * 5;
  C. UnaryOperator funIntf = n -> n * 5;
  D. IntFuction funIntf = n -> n * 5;
  C. UnaryOperator funIntf = n -> n * 5;

• Question 18:

  Given the incomplete pseudo-code for a fork/join framework application:

  

  And given the missing methods: process, submit, and splitInHalf

  Which three insertions properly complete the pseudo-code? (Choose three.)

  A. Insert process at line Z.
  B. Insert process at line X.
  C. Insert submit at line X.
  D. Insert splitInHalf at line X.
  E. Insert process at line Y.
  F. Insert splitInHalf at line Y.
  G. Insert submit at line Z.
  B. Insert process at line X.
  F. Insert splitInHalf at line Y.
  G. Insert submit at line Z.

  ---

  B: If the size is small enough then process the work.

  D: If the size is not small enough then slit up the wok in half.

  G: Submit the two split up pieces of work recursively.

  Note: Your code should look similar to the following pseudocode:

  

  Reference: https://docs.oracle.com/javase/tutorial/essential/concurrency/forkjoin.html

• Question 19:

  Given the fragment:

  

  Which code fragment, when inserted at line n1, enables the code to print ABCD?

  A. String str = sList.stream().reduce("",(s1, s2) -> s1.concat(s2));
  B. String str = sList.stream().reduce("A",(s1, s2) -> s1.concat(s2));
  C. String str = sList.stream().reduce((s1, s2) -> s1.concat(s2));
  D. String str = sList.stream().reduce("A",String::concat);
  A. String str = sList.stream().reduce("",(s1, s2) -> s1.concat(s2));

  ---

  The java.util.Arrays.asList(T... a) returns a fixed-size list backed by the specified array.

  Note: Use the following import statements to be able to run the code.

  import java.util.Arrays;

  import java.util.List;

  Incorrect Answers:

  B, D: Output is AABCD

  Reference: https://www.tutorialspoint.com/java/util/arrays_aslist.htm

• Question 20:

  Given the code fragments:

  

  and

  

  What is the result?

  A. A compilation error occurs at line n2.
  B. The program prints Run... and throws an exception.
  C. Run... Call...
  D. A compilation errors occurs at line n1.
  A. A compilation error occurs at line n2.