1z1-830試験無料問題集（85題）「Oracle Java SE 21 Developer Professional 認定」

出題：1

Which of the following can be the body of a lambda expression?

A. Two statements

B. None of the above

C. A statement block

D. An expression and a statement

E. Two expressions

正解：C 解答を投票する

解説: (GoShiken メンバーにのみ表示されます)

出題：2

Given:
java
DoubleSummaryStatistics stats1 = new DoubleSummaryStatistics();
stats1.accept(4.5);
stats1.accept(6.0);
DoubleSummaryStatistics stats2 = new DoubleSummaryStatistics();
stats2.accept(3.0);
stats2.accept(8.5);
stats1.combine(stats2);
System.out.println("Sum: " + stats1.getSum() + ", Max: " + stats1.getMax() + ", Avg: " + stats1.getAverage()); What is printed?

A. Sum: 22.0, Max: 8.5, Avg: 5.5

B. Compilation fails.

C. An exception is thrown at runtime.

D. Sum: 22.0, Max: 8.5, Avg: 5.0

正解：A 解答を投票する

解説: (GoShiken メンバーにのみ表示されます)

出題：3

Given:
java
StringBuffer us = new StringBuffer("US");
StringBuffer uk = new StringBuffer("UK");
Stream<StringBuffer> stream = Stream.of(us, uk);
String output = stream.collect(Collectors.joining("-", "=", ""));
System.out.println(output);
What is the given code fragment's output?

A. US-UK

B. -US=UK

C. Compilation fails.

D. =US-UK

E. US=UK

F. An exception is thrown.

正解：D 解答を投票する

解説: (GoShiken メンバーにのみ表示されます)

出題：4

Which of the following suggestions compile?(Choose two.)

A. java
public sealed class Figure
permits Circle, Rectangle {}
final sealed class Circle extends Figure {
float radius;
}
non-sealed class Rectangle extends Figure {
float length, width;
}

B. java
sealed class Figure permits Rectangle {}
final class Rectangle extends Figure {
float length, width;
}

C. java
public sealed class Figure
permits Circle, Rectangle {}
final class Circle extends Figure {
float radius;
}
non-sealed class Rectangle extends Figure {
float length, width;
}

D. java
sealed class Figure permits Rectangle {}
public class Rectangle extends Figure {
float length, width;
}

正解：B,C 解答を投票する

解説: (GoShiken メンバーにのみ表示されます)

出題：5

Which of the following doesnotexist?

A. DoubleSupplier

B. BooleanSupplier

C. BiSupplier<T, U, R>

D. Supplier<T>

E. LongSupplier

F. They all exist.

正解：C 解答を投票する

解説: (GoShiken メンバーにのみ表示されます)

出題：6

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. Nothing

B. Compilation fails.

C. An exception is thrown at runtime.

D. vbnet
Quand il me prend dans ses bras
Qu'il me parle tout bas
Je vois la vie en rose

正解：B 解答を投票する

解説: (GoShiken メンバーにのみ表示されます)

出題：7

Given:
java
public class BoomBoom implements AutoCloseable {
public static void main(String[] args) {
try (BoomBoom boomBoom = new BoomBoom()) {
System.out.print("bim ");
throw new Exception();
} catch (Exception e) {
System.out.print("boom ");
}
}
@Override
public void close() throws Exception {
System.out.print("bam ");
throw new RuntimeException();
}
}
What is printed?

A. bim bam boom

B. Compilation fails.

C. bim boom bam

D. bim bam followed by an exception

E. bim boom

正解：A 解答を投票する

解説: (GoShiken メンバーにのみ表示されます)

出題：8

Given:
java
String colors = "red\n" +
"green\n" +
"blue\n";
Which text block can replace the above code?

A. None of the propositions

B. java
String colors = """
red \t
green\t
blue \t
""";

C. java
String colors = """
red \s
green\s
blue \s
""";

D. java
String colors = """
red \
green\
blue \
""";

E. java
String colors = """
red
green
blue
""";

正解：E 解答を投票する

解説: (GoShiken メンバーにのみ表示されます)

1z1-830試験無料問題集「Oracle Java SE 21 Developer Professional 認定」