Free Oracle 1Z0-830 Exam Questions

Become Oracle Certified with updated 1Z0-830 exam questions and correct answers

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Total 84 Questions | Updated On: Oct 29, 2025

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Question 1

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 : 42000E

B : 42 000,00 €

C : 42000

D : 42 k

Answer: D

Question 2

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'}); } }

A : None of them

B : stringBuilder4

C : stringBuilder1

D : stringBuilder3

E : stringBuilder2

Answer: B

Question 3

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

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 4

Given: java

String bread = optionalName.orElse("Baguette"); System.out.print("bread:" + bread); String dish = optionalName.orElseGet(() -> "Frog legs"); System.out.print(", dish:" + dish); try { String cheese = optionalName.orElseThrow(() -> new Exception()); System.out.println(", cheese:" + cheese); } catch (Exception exc) { System.out.println(", no cheese."); } What is printed?

A : bread:Baguette, dish:Frog legs, cheese.

B : bread:Baguette, dish:Frog legs, no cheese.

C : bread:bread, dish:dish, cheese.

D : Compilation fails.

Answer: B

Question 5

Which methods compile?

A :