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

1. Given:
java
interface SmartPhone {
boolean ring();
}
class Iphone15 implements SmartPhone {
boolean isRinging;
boolean ring() {
isRinging = !isRinging;
return isRinging;
}
}
Choose the right statement.

A) Iphone15 class does not compile
B) An exception is thrown at running Iphone15.ring();
C) Everything compiles
D) SmartPhone interface does not compile

2. Given:
java
Period p = Period.between(
LocalDate.of(2023, Month.MAY, 4),
LocalDate.of(2024, Month.MAY, 4));
System.out.println(p);
Duration d = Duration.between(
LocalDate.of(2023, Month.MAY, 4),
LocalDate.of(2024, Month.MAY, 4));
System.out.println(d);
What is the output?

A) P1Y
PT8784H
B) P1Y
UnsupportedTemporalTypeException
C) PT8784H
P1Y
D) UnsupportedTemporalTypeException

3. 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) 2 1 2
C) 2 2 1
D) 1 1 1
E) 1 2 2
F) An exception is thrown.
G) 1 1 2
H) 2 1 1
I) 2 2 2

4. Given:
java
var ceo = new HashMap<>();
ceo.put("Sundar Pichai", "Google");
ceo.put("Tim Cook", "Apple");
ceo.put("Mark Zuckerberg", "Meta");
ceo.put("Andy Jassy", "Amazon");
Does the code compile?

A) True
B) False

5. Given:
java
double amount = 42_000.00;
NumberFormat format = NumberFormat.getCompactNumberInstance(Locale.FRANCE, NumberFormat.Style.
SHORT);
System.out.println(format.format(amount));
What is the output?

A) 42000
B) 42000E
C) 42 k
D) 42 000,00 €

質問と回答：