1z0-830 試験問題を無料オンラインアクセス

Given:
java
Integer frenchRevolution = 1789;
Object o1 = new String("1789");
Object o2 = frenchRevolution;
frenchRevolution = null;
Object o3 = o2.toString();
System.out.println(o1.equals(o3));
What is printed?

• A.false
• B.true
• C.Compilation fails.
• D.A NullPointerException is thrown.
• E.A ClassCastException is thrown.

Which of the following statements oflocal variables declared with varareinvalid?(Choose 4)

• A.var f = { 6 };
• B.var d[] = new int[4];
• C.var e;
• D.var h = (g = 7);
• E.var b = 2, c = 3.0;
• F.var a = 1;(Valid: var correctly infers int)

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

Which of the following statements is correct about a final class?

• A.It cannot implement any interface.
• B.It cannot be extended by any other class.
• C.It must contain at least a final method.
• D.It cannot extend another class.
• E.The final keyword in its declaration must go right before the class keyword.

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.ABC
• C.An exception is thrown.
• D.Compilation fails.