최신 Java SE 1z1-830 무료샘플문제:

1. 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: 5.0
B) An exception is thrown at runtime.
C) Sum: 22.0, Max: 8.5, Avg: 5.5
D) Compilation fails.

2. 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) An exception is thrown.
C) US-UK
D) Compilation fails.
E) -US=UK
F) US=UK

3. Given:
java
Optional o1 = Optional.empty();
Optional o2 = Optional.of(1);
Optional o3 = Stream.of(o1, o2)
.filter(Optional::isPresent)
.findAny()
.flatMap(o -> o);
System.out.println(o3.orElse(2));
What is the given code fragment's output?

A) An exception is thrown
B) Optional[1]
C) Compilation fails
D) 1
E) Optional.empty
F) 0
G) 2

4. Given:
java
DoubleStream doubleStream = DoubleStream.of(3.3, 4, 5.25, 6.66);
Predicate<Double> doublePredicate = d -> d < 5;
System.out.println(doubleStream.anyMatch(doublePredicate));
What is printed?

A) An exception is thrown at runtime
B) 3.3
C) false
D) Compilation fails
E) true

5. Given:
java
Object input = 42;
String result = switch (input) {
case String s -> "It's a string with value: " + s;
case Double d -> "It's a double with value: " + d;
case Integer i -> "It's an integer with value: " + i;
};
System.out.println(result);
What is printed?

A) null
B) It's an integer with value: 42
C) It's a string with value: 42
D) It's a double with value: 42
E) It throws an exception at runtime.
F) Compilation fails.

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