Exam 1z0-808 topic 1 question 52 discussion

Actual exam question from Oracle's 1z0-808

Question #: 52
Topic #: 1

[All 1z0-808 Questions]

Given the code fragment:

What is the result?

A. Element 0 Element 1
B. Null element 0 Null element 1
C. Null Null
D. A NullPointerException is thrown at runtime.

Show Suggested Answer

Suggested Answer: D 🗳️

by letmein2 at June 16, 2019, 11:49 p.m.

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Saftschnitzel

Highly Voted 5 years, 3 months ago

To add to the explanation: The JVM throws a null pointer exception because a method (concat()) is called on an object containing null. Note that the print() method does not cause JVM to throw an exception and prints null.

upvoted 23 times

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letmein2

Highly Voted 6 years ago

correct. null pointer is thrown at the line strs[idx].concat("element" + idx); because strs[0] is null.

upvoted 6 times

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vic88

Most Recent 7 months, 1 week ago

Selected Answer: D

D is right. During each iteration: First iteration (idx = 0): strs[0] is null. strs[idx].concat(" element " + idx) attempts to call concat on null, which leads to a NullPointerException.

upvoted 1 times

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Vicky_65

2 years, 3 months ago

Selected Answer: D

D is correct

upvoted 1 times

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odzio33

2 years, 5 months ago

Selected Answer: D

String[] strings = new String[2]; int idx = 0; for(String s : strings){ strings[idx].concat(" element " + idx); idx++; } for (idx = 0; idx < strings.length; idx++){ System.out.println(strings[idx]); } Exception in thread "main" java.lang.NullPointerException

upvoted 1 times

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