Java Standard Edition 6 Programmer Certified Professional Exam (1Z0-851) Free Practice Test

Question 1

Given:
10.interface Data { public void load(); }
11.abstract class Info { public abstract void load(); } Which class correctly uses the Data interface and Info class?

A. public class Employee extends Info implements Data {
public void load() { /*do something*/ }
}

B. public class Employee extends Info implements Data {
public void load(){ /*do something*/ } public void Info.load(){ /*do something*/ } }

C. public class Employee implements Info extends Data {
public void load() { /*do something*/ }
}

D. public class Employee implements Info extends Data {
public void Data.load(){ /*do something*/ }
public void load(){ /*do something*/ }
}

E. public class Employee extends Info implements Data{
public void Data.load() { /*do something*/ }
public void Info.load() { /*do something*/ }
}

F. public class Employee implements Info extends Data {
public void load(){ /*do something*/ }
public void Info.load(){ /*do something*/ }
}

Correct Answer: A

Question 2

Given:
1.interface DoStuff2 {
2.float getRange(int low, int high); }
3.4.
interface DoMore {
5.float getAvg(int a, int b, int c); }
6.7.
abstract class DoAbstract implements DoStuff2, DoMore { }
8.9.
class DoStuff implements DoStuff2 {
10.public float getRange(int x, int y) { return 3.14f; } }
11.12.
interface DoAll extends DoMore {
13.float getAvg(int a, int b, int c, int d); } What is the result?

A. Compilation fails. Only line 12 contains an error.

B. Compilation fails. Lines 7, 12, and 13 contain errors.

C. Compilation fails. Only line 13 contains an error.

D. Compilation fails. Only lines 7 and 13 contain errors.

E. Compilation fails. Only line 7 contains an error.

F. Compilation fails. Only lines 7 and 12 contain errors.

G. The file will compile without error.

Correct Answer: G

Question 3

Given:
1.public class Drink implements Comparable {
2.public String name;
3.public int compareTo(Object o) {
4.return 0;
5.}
6.} and:
20.Drink one = new Drink();
21.Drink two = new Drink();
22.one.name= "Coffee";
23.two.name= "Tea";
24.TreeSet set = new TreeSet();
25.set.add(one);
26.set.add(two);
A programmer iterates over the TreeSet and prints the name of each Drink object. What is the result?

A. Coffee

B. Tea

C. An exception is thrown at runtime.

D. Compilation fails.

E. The code runs with no output.

F. Coffee Tea

Correct Answer: A

Question 4

Given:
11.public static void main(String[] args) {
12.try {
13.args = null;
14.args[0] = "test";
15.System.out.println(args[0]);
16.} catch (Exception ex) {
17.System.out.println("Exception");
18.} catch (NullPointerException npe) {
19.System.out.println("NullPointerException");
20.}
21.}
What is the result?

A. Exception

B. Compilation fails.

C. test

D. NullPointerException

Correct Answer: B

Question 5

Given:
1.package com.company.application;
2.3.
public class MainClass {
4.public static void main(String[] args) {}
5.} And MainClass exists in the /apps/com/company/application directory. Assume the CLASSPATH environment variable is set to "." (current directory).
Which two java commands entered at the command line will run MainClass? (Choose two.)

A. java com.company.application.MainClass if run from the /apps directory

B. java MainClass if run from the /apps directory

C. java -classpath /apps/com/company/application:. MainClass if run from the /apps directory

D. java -classpath . MainClass if run from the /apps/com/company/application directory

E. java com.company.application.MainClass if run from the /apps/com/company/application directory

F. java -classpath /apps com.company.application.MainClass if run from any directory

Correct Answer: A,F

Question 6

Given:
5.class Payload {
6.private int weight;
7.public Payload (int w) { weight = w; }
8.public void setWeight(int w) { weight = w; }
9.public String toString() { return Integer.toString(weight); }
10.}
11.public class TestPayload {
12.static void changePayload(Payload p) { /* insert code */ }
13.public static void main(String[] args) {
14.Payload p = new Payload(200);
15.p.setWeight(1024);
16.changePayload(p);
17.System.out.println("p is " + p);
18.} }
Which code fragment, inserted at the end of line 12, produces the output p is 420?

A. Payload.setWeight(420);

B. p.changePayload(420);

C. p = new Payload(420);

D. p.setWeight(420);

E. p = Payload.setWeight(420);

Correct Answer: D

Question 7

Given:
11.class X { public void foo() { System.out.print("X "); } }
12.13.
public class SubB extends X {
14.public void foo() throws RuntimeException {
15.super.foo();
16.if (true) throw new RuntimeException();
17.System.out.print("B ");
18.}
19.public static void main(String[] args) {
20.new SubB().foo();
21.}
22.}
What is the result?

A. No output, and an Exception is thrown.

B. X, followed by an Exception, followed by B.

C. Compilation fails due to an error on line 14.

D. Compilation fails due to an error on line 17.

E. X, followed by an Exception.

F. Compilation fails due to an error on line 16.

Correct Answer: E

Question 8

DRAG DROP
Click the Task button.

Correct Answer:

Question 9

Which statement is true?

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

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

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

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

Correct Answer: C

Question 10

Given:
11.static class A {
12.void process() throws Exception { throw new Exception(); }
13.}
14.static class B extends A {
15.void process() { System.out.println("B"); }
16.}
17.public static void main(String[] args) {
18.new B().process();
19.}
What is the result?

A. B

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

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

D. The code runs with no output.

E. Compilation fails because of an error in line 18.

Correct Answer: A

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Oracle Java Standard Edition 6 Programmer Certified Professional (1Z0-851) Free Practice Test