Oracle 1Z0-813 Online Practice Questions and Exam Preparation

Oracle 1Z0-813 Online Questions & Answers

• Question 41:

  Which two elements must be present in any valid pipeline? (Choose two.)

  A. a lambda expression or a method reference
  B. a source
  C. one or more intermediate operations
  D. a reduction operation
  E. a terminal operation
  B. a source
  E. a terminal operation

  ---

  A stream pipeline consists of a source (such as a Collection, an array, a generator function, or an I/O channel); followed by zero or more intermediate operations such as Stream.filter or Stream.map; and a terminal operation such as Stream.forEach or Stream.reduce.

  Reference: https://docs.oracle.com/javase/8/docs/api/java/util/stream/package-summary.html

• Question 42:

  In 2015. daylight saving time in New York, USA, begins on March 8th at 2:00 AM. As a result, 2:00 AM becomes 3:00 AM.

  Given the code fragment:

  

  Which is the result?

  A. 2:00 -difference: 1
  B. 3:00 -difference: 2
  C. 4:00 -difference: 3
  D. 4:00 -difference: 2
  D. 4:00 -difference: 2

  ---

  Reference: http://docs.oracle.com/javase/8/docs/api/java/time/ZoneId.html

• Question 43:

  You are asked to implement an interface that processes a batch of transaction objects and returns a discounted value for each transaction as a double primitive value.

  Which interface can you use to accomplish this task?

  A. ToDoubleFunction
  B. DoubleSupplier
  C. DoubleFunction
  D. DoubleConsumer
  A. ToDoubleFunction

  ---

  The Interface ToDoubleFunction is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference. It represents a function that produces a double-valued result. This is the double-producing primitive specialization for Function.

  Incorrect Answers:

  B: The Interface DoubleSupplier is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference. It represents a supplier of double-valued results. This is the double-producing primitive specialization of Supplier.

  C: The Interface DoubleFunction is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference. It represents a function that accepts a double-valued argument and produces a result.

  D: The Interface DoubleConsumer represents an operation that accepts a single double-valued argument and returns no result.

  Reference: http://docs.oracle.com/javase/8/docs/api/java/util/function/ToDoubleFunction.html

• Question 44:

  Given the code fragments:

  

  and

  

  What is the result?

  A. An exception is thrown at runtime.
  B. A compilation error occurs.
  C. Jack Jane
  D. Jack Jane John Tom Tim
  A. An exception is thrown at runtime.

  ---

  p is not recognized in the line:

  persons.forEach -> System.out.print(p.getName() + " ");

  and an exception is thrown at runtime.

  Exception in thread "main" java.lang.RuntimeException: Uncompilable source code - not a statement

• Question 45:

  Given:

  

  and the code fragment:

  

  Which code fragment, when inserted at line n1, enables the Birdie class to compile?

  

  A. Option A
  B. Option B
  C. Option C
  D. Option D
  C. Option C

• Question 46:

  Which is true the regarding the java.nio.file.Path interface?

  A. Implementations of this interface are not safe for use by multiple concurrent threads.
  B. The interface extends the WatchService interface.
  C. Implementations of this interface are immutable.
  D. Paths associated with the default provider are not interoperable with the java.io.File class.
  B. The interface extends the WatchService interface.

  ---

  This interface extends Watchable interface so that a directory located by a path can be registered with a WatchService and entries in the directory watched.

  Reference: https://docs.oracle.com/javase/7/docs/api/java/nio/file/Path.html

• Question 47:

  Given: What is the result when you compile the code and execute the command: java MyApp kava

  

  A. kava
  B. Kava
  C. kawa
  D. Kawa
  E. An exception is thrown at runtime.
  D. Kawa

• Question 48:

  Given the code fragment:

  

  Which two code fragments, when inserted independently at line 6, enable the code to print true? (Choose two.)

  A. boolean b = nums.stream() .noneMatch(n -> n==20);
  B. boolean b = nums.stream() .filter(n -> n == 20) .allMatch(n -> n == 20);
  C. boolean b = nums.stream() .filter(n -> n == 20) .noneMatch(n -> n == 20);
  D. boolean b = nums.stream() .map(n -> 20) .noneMatch(n -> n == 10);
  E. boolean b = nums.stream() .allMatch(n -> n == 20);
  B. boolean b = nums.stream() .filter(n -> n == 20) .allMatch(n -> n == 20);
  D. boolean b = nums.stream() .map(n -> 20) .noneMatch(n -> n == 10);

• Question 49:

  Given the code fragment:

  

  What is the result?

  A. 0 0
  B. 1 2
  C. 1 4
  D. A compilation error occurs
  D. A compilation error occurs

  ---

  A compilation error will occur at the following line: map.compute("1", (k, v) -> (v == null) ? k * k : 0 );

  The error is: Exception in thread "main" java.lang.RuntimeException: Uncompilable source code - bad operand types for binary operator '*' first type: java.lang.String second type: java.lang.String

• Question 50:

  Given:

  

  and the code fragment:

  

  Which two code fragments, when inserted at line n1 independently, enable the code print TruckCarBike? (Choose two.)

  A. .sorted(Comparable.comparing(Vehicle::getVName)).reversed()
  B. .sorted((v1, v2) -> Integer.compare(v1.getVId(), v2.getVId()))
  C. .sorted((v1, v2) -> v1.getVId() < v2.getVId())
  D. .map(v -> v.getVId()) .sorted()
  E. .sorted(Comparator.comparing((Vehicle v) -> v.getVId()))
  B. .sorted((v1, v2) -> Integer.compare(v1.getVId(), v2.getVId()))
  E. .sorted(Comparator.comparing((Vehicle v) -> v.getVId()))