Question 1

Which StringBuilder variable fails to compile? java public class StringBuilderInstantiations { public static void main(String[] args) { var stringBuilder1 = new StringBuilder(); var stringBuilder2 = new StringBuilder(10); var stringBuilder3 = new StringBuilder("Java"); var stringBuilder4 = new StringBuilder(new char[]{'J', 'a', 'v', 'a'}); } }

Options :

A : None of them

B : stringBuilder4

C : stringBuilder1

D : stringBuilder3

E : stringBuilder2

Answer: B

Question 2

Given: java public class Test { public static void main(String[] args) throws IOException { Path p1 = Path.of("f1.txt"); Path p2 = Path.of("f2.txt"); Files.move(p1, p2); Files.delete(p1); } } In which case does the given program throw an exception?

Options :

A : Neither files f1.txt nor f2.txt exist

B : Both files f1.txt and f2.txt exist

C : An exception is always thrown

D : File f2.txt exists while file f1.txt doesn't

E : File f1.txt exists while file f2.txt doesn't

Answer: C

Question 3

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?

Options :

A : 42000E

B : 42 000,00 €

C : 42000

D : 42 k

Answer: D

Question 4

Which of the following statements oflocal variables declared with varareinvalid?(Choose 4)

Options :

A : var a = 1;(Valid: var correctly infers int)

B : var b = 2, c = 3.0;

C : var d[] = new int[4];

D : var e;

E : var f = { 6 };

F : var h = (g = 7);

Answer: B,C,D,E

Question 5

Which three of the following are correct about the Java module system?

Options :

A : Code in an explicitly named module can access types in the unnamed module.

B : The unnamed module exports all of its packages.

C : If a package is defined in both a named module and the unnamed module, then the package in the unnamed module is ignored.

D : We must add a module descriptor to make an application developed using a Java version prior to SE9 run on Java 11.

E : The unnamed module can only access packages defined in the unnamed module.

F : If a request is made to load a type whose package is not defined in any known module, then the module system will attempt to load it from the classpath.

Answer: B,C,F

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