Exam 1z0-809 topic 1 question 11 discussion

Actual exam question from Oracle's 1z0-809

Question #: 11
Topic #: 1

Given the code fragment:
Stream<List<String>> iStr= Stream.of (
Arrays.asList ("1", "John"),
Arrays.asList ("2", null));
Stream<<String> nInSt = iStr.flatMapToInt ((x) -> x.stream ()); nInSt.forEach (System.out :: print);
What is the result?

A. 1John2null
B. 12
C. A NullPointerException is thrown at run time.
D. A compilation error occurs.

Show Suggested Answer

Suggested Answer: D 🗳️

by M_Jawad at Jan. 13, 2020, 12:36 p.m.

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Innovation

Highly Voted 4 years, 11 months ago

D, a compile error occurs. if we change "Stream<String> nInSt = iStr.flatMapToInt((x) -> x.stream ());" to "Stream<String> nInSt = iStr.flatMap((x) -> x.stream ());" then the output is 1John2null

upvoted 16 times

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asdfjhfgjuaDCV

Most Recent 9 months, 4 weeks ago

D is the correct answer

upvoted 1 times

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steefaand

10 months, 3 weeks ago

Selected Answer: D

D is correct since x.stream() return Stream of String and not int.

upvoted 1 times

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Shad657

1 year, 5 months ago

Compilation error: incompatible types: bad return type in lambda expression Stream<String> nInSt = iStr.flatMapToInt((x) -> x.stream()); ^ Stream<String> cannot be converted to IntStream

upvoted 2 times

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