1z0-830最も有効な質問と解答で勉強

Oracle Java SE 21 Developer Professionalは業界で広く認知された資格であり、取得はキャリアの信頼性を高める確かな一歩となります。Tech4Examの1z0-830問題集は85問を収録し、公式の出題範囲に沿って学習を組み立てられます。

Oracle 1z0-830 試験概要:

Oracle 1z0-830 試験シラバストピック:

1z0-830に挑戦する方へ – よくある質問まとめ

Oracle Java SE 21 Developer Professional 認定 1z0-830 試験問題：

問題 #1

Given:
java
Deque<Integer> deque = new ArrayDeque<>();
deque.offer(1);
deque.offer(2);
var i1 = deque.peek();
var i2 = deque.poll();
var i3 = deque.peek();
System.out.println(i1 + " " + i2 + " " + i3);
What is the output of the given code fragment?

A. 1 2 1
B. 1 2 2
C. An exception is thrown.
D. 1 1 2
E. 2 1 2
F. 1 1 1
G. 2 1 1
H. 2 2 2
I. 2 2 1

問題 #2

Which of the following methods of java.util.function.Predicate aredefault methods?

A. test(T t)
B. isEqual(Object targetRef)
C. negate()
D. or(Predicate<? super T> other)
E. not(Predicate<? super T> target)
F. and(Predicate<? super T> other)

問題 #3

Given:
java
public static void main(String[] args) {
try {
throw new IOException();
} catch (IOException e) {
throw new RuntimeException();
} finally {
throw new ArithmeticException();
}
}
What is the output?

A. IOException
B. Compilation fails
C. RuntimeException
D. ArithmeticException

問題 #4

Which three of the following are correct about the Java module system?

A. We must add a module descriptor to make an application developed using a Java version prior to SE9 run on Java 11.
B. If a package is defined in both a named module and the unnamed module, then the package in the unnamed module is ignored.
C. If a request is made to load a type whose package is not defined in any known module, then the module system will attempt to load it from the classpath.
D. Code in an explicitly named module can access types in the unnamed module.
E. The unnamed module exports all of its packages.
F. The unnamed module can only access packages defined in the unnamed module.

問題 #5

Given:
java
var lyrics = """
Quand il me prend dans ses bras
Qu'il me parle tout bas
Je vois la vie en rose
""";
for ( int i = 0, int j = 3; i < j; i++ ) {
System.out.println( lyrics.lines()
.toList()
.get( i ) );
}
What is printed?

A. Compilation fails.
B. vbnet
Quand il me prend dans ses bras
Qu'il me parle tout bas
Je vois la vie en rose
C. An exception is thrown at runtime.
D. Nothing

解説：