Oracle 1Z0-851 Actual Free Exam Questions & Community Discussion

Exam Code/Number: 1Z0-851
Exam Name/Title: Java Standard Edition 6 Programmer Certified Professional Exam
Certification Provider: Oracle
Corresponding Certification: OCJP

Exam Questions: 290
Updated On: May 26, 2026

Question #27

Given that the current directory is empty, and that the user has read and write privileges to the current directory, and the following:
1.import java.io.*;
2.public class Maker {
3.public static void main(String[] args) {
4.File dir = new File("dir");
5.File f = new File(dir, "f");
6.}
7.}
Which statement is true?

A. Only a new file is created on the file system.

B. Compilation fails.

C. Both a new file and a new directory are created on the file system.

D. Only a new directory is created on the file system.

E. Nothing is added to the file system.

Discussion 0

Correct Answer: E Vote an answer

Question #28

Given:
22.public void go() {
23.String o = "";
24.z:
25.for(int x = 0; x < 3; x++) {
26.for(int y = 0; y < 2; y++) {
27.if(x==1) break;
28.if(x==2 && y==1) break z;
29.o = o + x + y;
30.}
31.}
32.System.out.println(o);
33.}
What is the result when the go() method is invoked?

A. Compilation fails.

B. 000120

C. 00

D. 0001

E. An exception is thrown at runtime.

F. 00012021

Discussion 0

Correct Answer: B Vote an answer

Question #29

Given:
11.public enum Title {
12.MR("Mr."), MRS("Mrs."), MS("Ms.");
13.private final String title;
14.private Title(String t) { title = t; }
15.public String format(String last, String first) {
16.return title + " " + first + " " + last;
17.}
18.}
19.public static void main(String[] args) {
20.System.out.println(Title.MR.format("Doe", "John"));
21.}
What is the result?

A. Compilation fails because of an error in line 15.

B. An exception is thrown at runtime.

C. Compilation fails because of an error in line 20.

D. Compilation fails because of an error in line 12.

E. Mr. John Doe

Discussion 0

Correct Answer: E Vote an answer

Question #30

Given:
1.public class Target {
2.private int i = 0;
3.public int addOne(){
4.return ++i;
5.}
6.} And:
1.public class Client {
2.public static void main(String[] args){
3.System.out.println(new Target().addOne());
4.}
5.}
Which change can you make to Target without affecting Client?

A. Line 2 of class Target can be changed to private int i = 1;

B. Line 3 of class Target can be changed to private int addOne(){

C. Line 4 of class Target can be changed to return i++;

D. Line 2 of class Target can be changed to private Integer i = 0;

Discussion 0

Correct Answer: D Vote an answer

Question #31

Which statement is true?

A. The order in which finalize() is called on two objects is based on the order in which the two objects became finalizable.

B. super.finalize() is called implicitly by any overriding finalize() method.

C. A class's finalize() method CANNOT be invoked explicitly.

D. The finalize() method for a given object is called no more than once by the garbage collector.

Discussion 0

Correct Answer: D Vote an answer

Question #32

Given:
10.interface Foo {}
11.class Alpha implements Foo {}
12.class Beta extends Alpha {}
13.class Delta extends Beta {
14.public static void main( String[] args ) {
15.Beta x = new Beta();
16.// insert code here
17.}
18.}
Which code, inserted at line 16, will cause a java.lang.ClassCastException?

A. Beta b = (Beta)(Alpha)x;

B. Foo f = (Delta)x;

C. Foo f = (Alpha)x;

D. Alpha a = x;

Discussion 0

Correct Answer: B Vote an answer

Question #33

Given: public class NamedCounter {
private final String name;
private int count;
public NamedCounter(String name) { this.name = name; }
public String getName() { return name; }
public void increment() { count++; }
public int getCount() { return count; }
public void reset() { count = 0; }
} Which three changes should be made to adapt this class to be used safely by multiple threads? (Choose three.)

A. declare getCount() using the synchronized keyword

B. declare the constructor using the synchronized keyword

C. declare increment() using the synchronized keyword

D. declare getName() using the synchronized keyword

E. declare reset() using the synchronized keyword

Discussion 0

Correct Answer: A,C,E Vote an answer

Question #34

DRAG DROP
Click the Task button.

Discussion 0

Correct Answer:

Question #35

Given:
11.public void genNumbers() {
12.ArrayList numbers = new ArrayList();
13.for (int i=0; i<10; i++) {
14.int value = i * ((int) Math.random());
15.Integer intObj = new Integer(value);
16.numbers.add(intObj);
17.}
18.System.out.println(numbers);
19.}
Which line of code marks the earliest point that an object referenced by intObj becomes a candidate for garbage collection?

A. Line 16

B. Line 18

C. Line 19

D. The object is NOT a candidate for garbage collection.

E. Line 17

Discussion 0

Correct Answer: C Vote an answer

Question #36

Given:
11.public interface A { public void m1(); }
12.13.
class B implements A { }
14.class C implements A { public void m1() { } }
15.class D implements A { public void m1(int x) { } }
16.abstract class E implements A { }
17.abstract class F implements A { public void m1() { } }
18.abstract class G implements A { public void m1(int x) { } } What is the result?

A. Exactly three classes do NOT compile.

B. Compilation succeeds.

C. Exactly two classes do NOT compile.

D. Exactly four classes do NOT compile.

E. Exactly one class does NOT compile.

Discussion 0

Correct Answer: C Vote an answer

Question #37

Which Man class properly represents the relationship "Man has a best friend who is a Dog"?

A. class Man implements Dog { }

B. class Man { private Dog<bestFriend>; }

C. class Man { private BestFriend<dog>; }

D. class Man { private Dog bestFriend; }

E. class Man { private BestFriend dog; }

F. class Man extends Dog { }

Discussion 0

Correct Answer: D Vote an answer

Question #38

Given:
11.static void test() throws Error {
12.if (true) throw new AssertionError();
13.System.out.print("test ");
14.}
15.public static void main(String[] args) {
16.try { test(); }
17.catch (Exception ex) { System.out.print("exception "); }
18.System.out.print("end ");
19.}
What is the result?

A. exception test end

B. exception end

C. Compilation fails.

D. A Throwable is thrown by main.

E. An Exception is thrown by main.

F. end

Discussion 0

Correct Answer: D Vote an answer

Question #39

Given:
11.public class Commander {
12.public static void main(String[] args) {
13.String myProp = /* insert code here */
14.System.out.println(myProp);
15.}
16.}
and the command line: java -Dprop.custom=gobstopper Commander Which two, placed on line 13, will produce the output gobstopper? (Choose two.)

A. System.getProperty("prop.custom");

B. System.getProperties().getProperty("prop.custom");

C. System.load("prop.custom");

D. System.property("prop.custom");

E. System.getenv("prop.custom");

Discussion 0

Correct Answer: A,B Vote an answer

Download Free Oracle 1Z0-851 Demo

Simply submit your e-mail address below to get started with our free demo of your Oracle 1Z0-851 exam.