最新の1z0-830問題集で試験を準備する

Given:
java
List<String> abc = List.of("a", "b", "c");
abc.stream()
.forEach(x -> {
x = x.toUpperCase();
});
abc.stream()
.forEach(System.out::print);
What is the output?

• A. ABC
• B. Compilation fails.
• C. An exception is thrown.
• D. abc

解説: (JPTestKing メンバーにのみ表示されます)

Given:
java
void verifyNotNull(Object input) {
boolean enabled = false;
assert enabled = true;
assert enabled;
System.out.println(input.toString());
assert input != null;
}
When does the given method throw a NullPointerException?

• A. Only if assertions are enabled and the input argument isn't null
• B. Only if assertions are disabled and the input argument isn't null
• C. Only if assertions are disabled and the input argument is null
• D. A NullPointerException is never thrown
• E. Only if assertions are enabled and the input argument is null

解説: (JPTestKing メンバーにのみ表示されます)

Given:
java
List<Long> cannesFestivalfeatureFilms = LongStream.range(1, 1945)
.boxed()
.toList();
try (var executor = Executors.newVirtualThreadPerTaskExecutor()) {
cannesFestivalfeatureFilms.stream()
.limit(25)
.forEach(film -> executor.submit(() -> {
System.out.println(film);
}));
}
What is printed?

• A. Numbers from 1 to 25 sequentially
• B. Numbers from 1 to 1945 randomly
• C. Numbers from 1 to 25 randomly
• D. An exception is thrown at runtime
• E. Compilation fails

解説: (JPTestKing メンバーにのみ表示されます)

What do the following print?
java
public class DefaultAndStaticMethods {
public static void main(String[] args) {
WithStaticMethod.print();
}
}
interface WithDefaultMethod {
default void print() {
System.out.print("default");
}
}
interface WithStaticMethod extends WithDefaultMethod {
static void print() {
System.out.print("static");
}
}

• A. static
• B. default
• C. nothing
• D. Compilation fails

解説: (JPTestKing メンバーにのみ表示されます)

Given:
java
sealed class Vehicle permits Car, Bike {
}
non-sealed class Car extends Vehicle {
}
final class Bike extends Vehicle {
}
public class SealedClassTest {
public static void main(String[] args) {
Class<?> vehicleClass = Vehicle.class;
Class<?> carClass = Car.class;
Class<?> bikeClass = Bike.class;
System.out.print("Is Vehicle sealed? " + vehicleClass.isSealed() +
"; Is Car sealed? " + carClass.isSealed() +
"; Is Bike sealed? " + bikeClass.isSealed());
}
}
What is printed?

• A. Is Vehicle sealed? false; Is Car sealed? false; Is Bike sealed? false
• B. Is Vehicle sealed? false; Is Car sealed? true; Is Bike sealed? true
• C. Is Vehicle sealed? true; Is Car sealed? false; Is Bike sealed? false
• D. Is Vehicle sealed? true; Is Car sealed? true; Is Bike sealed? true

解説: (JPTestKing メンバーにのみ表示されます)