1z0-819 Java SE 11 Developer Questions and Answers

javac fails to compile the class and prints the error message, C:\workspace4\Mycar.java:1:error: package java does not exist

javac compiles Mycar.java without errors or warnings.

javac fails to compile the class and prints the error message, C:\workspace4\Mycar.java:1:error: expected import java.lang

javac fails to compile the class and prints the error message, Error: Could not find or load main class Mycar.class

Option A

Option B

Option C

Option D

Option E

Option F

Insert Comparator on line 1.

Insert

public int compare(Person p1, Person p2) {

return p1.name.compare(p2.name);

}

on line 2.

Insert Comparator on line 1.

Insert

public int compareTo(Person person) {

return person.name.compareTo(this.name);

}

on line 2.

Insert Comparable on line 1.

Insert

public int compare(Person p1, Person p2) {

return p1.name.compare(p2.name);

}

on line 2.

Insert Comparator on line 1.

Insert

public int compare(Person person) {

return person.name.compare(this.name);

}

on line 2.

An indexOutofBoundsException is thrown at runtime.

At once 0

Hat at store 4

At once 1

Hat at store 1

It throws a runtime exception.

Value of Euler = 2.71828

The code does not compile.

Value of Euler = “2.71828”

385

3

The compilation fails.

80

25

Option A

Option B

Option C

Option D

Limit access to objects holding confidential information.

Clearly identify and label confidential information.

Manage confidential and other information uniformly.

Transparently handle information to improve diagnostics.

Treat user input as normal information.

Validate input before storing confidential information.

Encapsulate confidential information.

In Line 1, change the access modifier to privateprivate Person() {

In Line 1, change the access modifier to publicpublic Person() {

In Line 2, add extends Person to the Main classpublic class Main extends Person {and change Line 3 to create a new Main objectPerson person = new Main();

In Line 2, change the access modifier to protectedprotected class Main {

In Line 1, remove the access modifierPerson() {

@SuppressWarnings on the main and print methods

@SuppressWarnings(“unchecked”) on main and @SafeVarargs on the print method

@SuppressWarnings(“rawtypes”) on main and @SafeVarargs on the print method

@SuppressWarnings(“all”) on the main and print methods

ab cd ef

An ArrayIndexOutOfBoundsException is thrown at runtime.

The compilation fails.

abc def

ad be cf

Option A

Option B

Option C

Option D

Option E

final String getFirstLetter() { return A.toString(); }

static String getFirstLetter() { return Alphabet.values()[1].toString(); }

static String getFirstLetter() { return A.toString(); }

String getFirstLetter() { return A.toString(); }

data\another-project

data\projects\a-project\another-project

data\\projects\\a-project\\..\\..\\another-project

data\projects\a-project\..\..\another-project

A java.nio.file.FileAlreadyExistsException is thrown on line 1.

A java.nio.file.NoSuchFileException is thrown on line 2.

A copy of /repo/a/a.txt is moved to the /repo directory and /repo/a/a.txt is deleted.

a.txt is renamed repo.

jdeps lists the module dependencies and the package names of all referenced JDK internal APIs. If any are found, the suggested replacements are output in the console.

jdeps outputs an error message that the -jdkinternals option requires either the -summary or the - verbose options to output to the console.

The -jdkinternals option analyzes all classes in the .jar and prints all class-level dependencies.

The -jdkinternals option analyzes all classes in the .jar for class-level dependencies on JDK internal APIs. If any are found, the results with suggested replacements are output in the console.

3 5 3 3

3 3 3 3

3 5 3 5

5 5 3 3

Option A

Option B

Option C

Option D

Short value 25

The compilation fails due to an error in line 1.

Byte value 25

Object value 25

Option A

Option B

Option C

Option D

s.replace(s.indexOf(“A”), s.indexOf(“C”), “Q”);

s.replace(s.indexOf(“B”), s.indexOf(“C”), “Q”);

s.replace(s.indexOf(“B”), s.indexOf(“B”), “Q”);

s.replace(s.indexOf(“A”), s.indexOf(“B”), “Q”);

public String toString() { return String.valueOf(ALPHA.v); }

public String toString() { return String.valueOf(Letter.values()[1]); }

public String toString() { return String.valueOf(v); }

String toString() { return “200”; }

class, package, import

package, import, class

import, package, class

package, class, import

import, class, package

Option A

Option B

Option C

Option D

The compilation fails because there is no zero args constructor defined in class X.

The compilation fails because either class X or class Y needs to implement the toString() method.

The compilation fails because a final class cannot extend another class.

The compilation succeeds.

Input: Echo:

Input: Helloworld Echo: Helloworld

Input:

Then block until any input comes from System.in.

Input:

Echo: Helloworld

A NullPointerException is thrown at run time.

2

-1

1

-3

Car--red--My

My--Car--is

My--is--java

java--Myclass--My

Myclass--Car--red

public List foo(Set m) { ... }

public ArrayList foo(Set m) { ... }

public List foo(TreeSet m) { ... }

public List foo(Set m) { ... }

public List