1z1-830 Exam Question 1

Which of the followingisn'ta correct way to write a string to a file?
  • 1z1-830 Exam Question 2

    Given:
    java
    List<String> l1 = new ArrayList<>(List.of("a", "b"));
    List<String> l2 = new ArrayList<>(Collections.singletonList("c"));
    Collections.copy(l1, l2);
    l2.set(0, "d");
    System.out.println(l1);
    What is the output of the given code fragment?
  • 1z1-830 Exam Question 3

    Given:
    java
    interface A {
    default void ma() {
    }
    }
    interface B extends A {
    static void mb() {
    }
    }
    interface C extends B {
    void ma();
    void mc();
    }
    interface D extends C {
    void md();
    }
    interface E extends D {
    default void ma() {
    }
    default void mb() {
    }
    default void mc() {
    }
    }
    Which interface can be the target of a lambda expression?
  • 1z1-830 Exam Question 4

    Given:
    java
    System.out.print(Boolean.logicalAnd(1 == 1, 2 < 1));
    System.out.print(Boolean.logicalOr(1 == 1, 2 < 1));
    System.out.print(Boolean.logicalXor(1 == 1, 2 < 1));
    What is printed?
  • 1z1-830 Exam Question 5

    Given:
    java
    Optional o1 = Optional.empty();
    Optional o2 = Optional.of(1);
    Optional o3 = Stream.of(o1, o2)
    .filter(Optional::isPresent)
    .findAny()
    .flatMap(o -> o);
    System.out.println(o3.orElse(2));
    What is the given code fragment's output?