Practice Test 21 of  Java SE 17 certification exam 1Z0-829

Practice Test 21 of the free Java SE 17 Developer Professional certification exam 1Z0-829 series is for candidates weighing East Coast markets against a national midpoint. One 2026 guide estimated average Java base near $162,000 in Boston and $150,000 in Chicago, with Atlanta closer to $132,000. Startup hiring data has also shown a broad Java range from about $60,000 to $205,000, with an average near $114,000, which is a reminder that averages hide level. Inside that spread, juniors are often quoted near $75,000 to $106,500, mid-level developers near a $119,700 average, and seniors in many postings near $114,500 to $146,000 before equity. Java is one of the most popular languages enterprise companies use for backends that must last. Fidelity, T-Mobile, and Home Depot hire Java developers for finance, telecom, and retail systems in more than one city. This free practice test rehearses 1Z0-829 without charging an exam fee. Synergisticit JOPP helps jobseekers get certified, prepared, and hired at top tech companies through our Job Placement programs, Java DevOps Full Stack JOPP and Data Science JOPP. If you want to learn how to get hired as a Java programmer or a software engineer, contact Synergisticit.

Welcome to your Java Test 21 - 2024

Name

Email

Phone

Q1. Which of the following are valid module definitions?

You had to select 1 option(s)

//In file module.java:
module autos{
}

//In file autos.java:
module autos{
}

//In file module-info.java:
module autos{
}

//In file module-info.java:
module cars{
exports com.car;
}
module trucks{
requires cars;
}

//In file module-info.java:
module-info autos{
}
Module definition must start with module keyword, not module-info.
//In file module-info.java:
sealed module autos{
}

None

Q2. What will be the output of the following program:

public class TestClass{
public static void main(String args[]){
try{
m1();
}catch(IndexOutOfBoundsException e){
System.out.println("1");
throw new NullPointerException();
}catch(NullPointerException e){
System.out.println("2");
return;
}catch (Exception e) {
System.out.println("3");
}finally{
System.out.println("4");
}
System.out.println("END");
}

static void m1(){
System.out.println("m1 Starts");
throw new IndexOutOfBoundsException( "Big Bang " );
}
}

You had to select 3 option(s)

The program will print m1 Starts.

The program will print m1 Starts, 1 and 4, in that order.

The program will print m1 Starts, 1 and 2, in that order.

The program will print m1 Starts, 1, 2 and 4 in that order.

END will not be printed.

Q3. Replace XXX with a declaration such that the following code will compile without any error or warning.

public void m1(XXX list)
{
Number n = list.get(0);
}

You had to select 1 option(s)

None

Q4. Consider the following code...

class MyException extends Exception {}

public class TestClass{
public void myMethod() throws XXXX{
throw new MyException();
}
}

What can replace XXXX?

You had to select 3 option(s)

MyException

Exception

Because Exception is a superclass of MyException.

No throws clause is necessary

Throwable

RuntimeException

Q5. The following code snippet will print 4.

int i1 = 1, i2 = 2, i3 = 3;
int i4 = i1 + (i2=i3 );
System.out.println(i4);

You had to select 1 option(s)

True

False

None

Q6. What will the following code print when compiled and run?

import java.time.*;
import java.time.format.*;
public class DateTest{
public static void main(String[] args){ //1
LocalDateTime greatDay = LocalDateTime.parse("2022-01-01");//2
String greatDayStr = greatDay.format(DateTimeFormatter.ISO_DATE_TIME); //3
System.out.println(greatDayStr);//4
}
}

You had to select 1 option(s)

//1 will not compile because of lack of throws clause.

//2 will not compile because of invalid date string.

//2 will throw an exception at run time.

It will print 2022-01-01T00:00:00

It will print null.

None

Q7. Which of the following code fragments correctly loads a service provider that implements api.BloggerService?

You had to select 1 option(s)

None

Q8. What will the following code print when compiled and run?

class ABCD{
int x = 10;
static int y = 20;
}
class MNOP extends ABCD{
int x = 30;
static int y = 40;
}

public class TestClass {
public static void main(String[] args) {
System.out.println(new MNOP().x+", "+new MNOP().y);
}
}

You had to select 1 option(s)

10, 40

30, 20

10, 20

30, 40

20, 30

Compilation error.

None

Q9. Given:

StringBuilder sb = new StringBuilder("abcdef");
//INSERT CODE HERE
for(int i = 0, k = sb.length(); i<k; i++){
sb.replace(i, i+1, f.apply(sb.charAt(i)));
}
System.out.println(sb);

Which of the following statements can be inserted in the above code?

You had to select 1 option(s)

None

Q10. Which statements about the following code are correct?

interface House{
public default void lockTheGates(){
System.out.println("Locking House");
}
}

interface Office {
public void lockTheGates();
}

class HomeOffice implements House, Office{ //1
public void lockTheGates(){
System.out.println("Locking HomeOffice");
}
}

public class TestClass {

public static void main(String[] args) {
Office off = new HomeOffice(); //2
off.lockTheGates();
}
}

You had to select 1 option(s)

Code for class HomeOffice will cause compilation to fail.

Line at //1 will cause compilation to fail.

Line at //2 will cause compilation to fail.

The code will compile successfully if the lockTheGates method is removed from class HomeOffice.

It will compile fine and print Locking HomeOffice when run.

None

Q11. What will the following code print when compiled and run?

interface Pow{
static void wow(){
System.out.println("In Pow.wow");
}
}

abstract class Wow{

static void wow(){ // LINE 9
System.out.println("In Wow.wow");
}
}

public class Powwow extends Wow implements Pow {
public static void main(String[] args) {
Powwow f = new Powwow();
f.wow();
}
}

You had to select 2 option(s)

In Wow.wow

In Pow.wow

It will print In Pow.wow if f.wow() is replaced with ((Pow)f).wow();

It will not compile as is.

It will not compile if the line marked //LINE 9 is replaced with:
@Override
static void wow(){

Q12. Given:

//Insert code here

public abstract void draw();
}


//Insert code here
public void draw(){ System.out.println("in draw..."); }
}

Which of the following lines of code can be used to complete the above code?

You had to select 2 option(s)

sealed class Shape {

and

class Circle extends Shape {

public class Shape {

and

class Circle extends Shape {

abstract Shape {

and

public class Circle extends Shape {

public abstract class Shape {

and

class Circle extends Shape {
@Override

public abstract class Shape {

and

class Circle implements Shape {

public interface Shape {

and

class Circle implements Shape {
@Override

sealed abstract class Shape permits Circle{

and

class Circle extends Shape {

Q13. Consider the following code:

String[] dataList = {"x", "y", "z"};
for (var dataElement : dataList) {
int innerCounter = 0;
while (innerCounter < dataList.length) {
System.out.println(dataElement + ", " + innerCounter);
innerCounter++;
}

}

How many times will the output contain 2?

You had to select 1 option(s)

0

1

2

3

4

It will fail to compile.

None

Q14. Given:

class T extends Thread
{
public T(String name){ super(name); }

public void run()
{
try{
for(int i=0; i<2; i++){
Thread.sleep(1000);
System.out.println(getName()+" "+getState());
}
}catch(InterruptedException ie){
System.out.println(getName()+" "+getState()+" ");
}
}
}
public class TestClass
{
public static void main(String args[]) throws Exception
{
T t1 = new T("T1");
t1.start();
T t2 = new T("T2");
t2.start();
Thread.sleep(300);
t1.interrupt();
}
}

Which of the following is a possible output?

You had to select 2 option(s)

T1 RUNNABLE
T2 RUNNABLE
T2 RUNNABLE
T1 RUNNABLE

T1 RUNNABLE
T2 RUNNABLE
T2 RUNNABLE

T1 RUNNABLE
T2 RUNNABLE
T2 RUNNABLE
T1 TERMINATED

T1 TERMINATED
T2 RUNNABLE
T2 RUNNABLE

T2 RUNNABLE
T1 BLOCKED
T1 TERMINATED
T2 RUNNABLE

Q15. What will be printed by the following code if it is run with command line: java TestClass -0.50 ?

public class TestClass{
public static double getSwitch(String str){
return Double.parseDouble(str.substring(1, str.length()-1) );
}
public static void main(String args []){
switch(getSwitch(args[0])){
case 0.0 -> System.out.println("Hello");
case 1.0 -> { System.out.println("World"); break; }
default -> System.out.println("Good Bye");
}
}
}

You had to select 1 option(s)

Hello

World

Hello World

Hello World Good Bye

The code will not compile because the type of the switch selector expression is invalid.

The code will not compile because the usage of break is invalid.

None

Q16. Consider the following class:

public class Student implements Serializable{
public static final long serialVersionUID = 1;
public String name;
public String grade;
public String toString(){ return "["+name+", "+grade+"]"; }
}

An object of this class was created as follows and was serialized to a file c:\temp\bob.ser:
Student s = new Student();
s.name = "bob";
s.grade = "10";
After some time the Student class was changed as follows:
public class Student implements Serializable{
public static final long serialVersionUID = 1;
public String id="S111";
public String name;
public String grade;
public int age=15;
public String toString(){ return "["+id+", "+name+", "+grade+", "+age+"]"; }
}
Now, the serialized file is read back as follows:
FileInputStream fis = new FileInputStream("c:\\temp\\bob.ser");
ObjectInputStream is = new ObjectInputStream(fis);
s = (Student) is.readObject();
is.close();
System.out.println("Loaded "+s);

What will it print?

You had to select 1 option(s)

It will throw an exception while deserializing the file.

Loaded [null, bob, 10, 0]

Loaded [S111, bob, 10, 15]

It will have unpredicable values for id and age.

None

Q17. What will the following command show?

jdeps --list-deps moduleA.jar

You had to select 2 option(s)

It will list all the modules on which moduleA depends.

It will list all the packages of all the modules on which moduleA depends.

It will list all the standard JDK modules on which moduleA depends.

It checks whether moduleA.jar contains all the required modules and prints the ones not present.

It will show an error if moduleA requires any other application module.

Q18. What will the following code print?

Stream ss = Stream.of("a", "b", "c");
String str = ss.collect(Collectors.joining(",", "-", "+"));
System.out.println(str);

You had to select 1 option(s)

-a+,-b+,-c+

a,-+b,-+c

-a,b,c+

It will throw an exception at run time.

None

Q19. Which line will print the string "MUM"?

public class TestClass{

   public static void main(String args []){

      String s = "MINIMUM";

      System.out.println(s.substring(4, 7)); //1

      System.out.println(s.substring(5)); //2

      System.out.println(s.substring(s.indexOf('I', 3))); //3

      System.out.println(s.substring(s.indexOf('I', 4))); //4

   }

}

 

You had to select 1 option(s)

1

2

3

4

None of these.

None

Q20. Given:

import java.util.*;
public class TestClass {
public static void main(String[] args) throws Exception {
ArrayList al = new ArrayList();

//INSERT CODE HERE
}
}

What can be inserted in the above code so that it can compile without any error?

You had to select 2 option(s)

al.add(111);

System.out.println(al.indexOf(1.0));

System.out.println(al.contains("string"));

Double d = al.get(al.length);

Q21. What will be the output of the following program ?

class CorbaComponent{
String ior;
CorbaComponent(){ startUp("IOR"); }
void startUp(String s){ ior = s; }
void print(){ System.out.println(ior); }
}

class OrderManager extends CorbaComponent{
OrderManager(){ }
void startUp(String s){ ior = getIORFromURL(s); }
String getIORFromURL(String s){ return "URL://"+s; }
}

public class Application{
public static void main(String args[]){ start(new OrderManager()); }
static void start(CorbaComponent cc){ cc.print(); }
}

You had to select 1 option(s)

It will throw an exception at run time.

It will print IOR

It will print URL://IOR

It will not compile.

None of the above.

None

Q22. You are using a RDBMS database from a company named Fandu Tech. It provides a JDBC 4.0 compliant driver implementation in class com.fandu.sql.Driver.

Which of the following lines of code is/are required to get the driver loaded?

You had to select 1 option(s)

Connection c = DriverManager.getConnection("jdbc:fandu://localhost:1234/myDB", "user", "pwd");
(Assume that the parameters are valid.)

Class.forName("com.fandu.sql.Driver");

This is required for JDBC 1.3 and older versions. Not for JDBC 4.0.

com.fandu.sql.Driver d = com.fandu.sql.Driver.class.newInstance()

DriverManager.loadDriver("com.fandu.sql.Driver");

None of the above.

None

Q23. Consider the following code:

public class Student {
private Map marksObtained
= new HashMap();
private ReadWriteLock lock = new ReentrantReadWriteLock();
public void setMarksInSubject(String subject, Integer marks){
// 1 INSERT CODE HERE
try{
marksObtained.put(subject, marks);
}finally{
// 2 INSERT CODE HERE
}

}
public double getAverageMarks(){
// valid code that computes average
}
}

What should be inserted at //1 and //2?

You had to select 1 option(s)

lock.writeLock().acquire();
and
lock.writeLock().release();

lock.writeLock().lock();
and
lock.writeLock().unlock();

lock.acquire();
and
lock.release();

lock.readLock().lock();
and
lock.readLock().unlock();

None

Q24. Consider the following method...

public int setVar(int a, int b, float c) { ...}

Which of the following methods correctly overload the above method?

You had to select 2 option(s)

public int setVar(int a, float b, int c){
return (int)(a + b + c);
}

public int setVar(int a, float b, int c){
return this(a, c, b);
}

public int setVar(int x, int y, float z){
return x+y;
}

public float setVar(int a, int b, float c){
return c*a;
}

public float setVar(int a){
return a;
}

Q25. Given:

public class Book {
private String title;
private LocalDate releaseDate;
public Book(String title, LocalDate releaseDate){
this.title = title; this.releaseDate = releaseDate;
}
//accessors not shown
}

and the following code:

var books = new ArrayList( List.of(
new Book("The Outsider", LocalDate.of(2019, 1, 1)),
new Book("Becoming", LocalDate.of(2018, 1, 1)),
new Book("Uri", LocalDate.of(2017, 1, 1))) );

Predicate p =
b->b.getReleaseDate()
.isAfter(IsoChronology.INSTANCE.date(2018, 1, 1));

Set newBooks = books.stream().
INSERT CODE HERE

What can be inserted in the code above so that newBooks will be assigned a set of books that were released after the date indicated by the predicate p?

You had to select 3 option(s)

.collect(Collectors.partitioningBy(p))
.get(true).stream().map(Book::getTitle).collect(Collectors.toCollection(TreeSet::new));

.collect(Collectors.partitioningBy(p))
.get(true).stream().map(Book::getTitle).collect(Collectors.toSet());

.collect(Collectors.partitioningBy(p,
Collectors.mapping(Book::getTitle, Collectors.toSet())));

.collect(Collectors.groupingBy(p,
Collectors.mapping(Book::getTitle, Collectors.toSet())));

.collect(Collectors.filtering(p,
Collectors.mapping(Book::getTitle, Collectors.toSet())));

Q26. Given that daylight Savings Time ends on Nov 6th 2021 at 2 AM in US/Eastern time zone. (As a result, 2 AM becomes 1 AM. In other words, one minute after 1.59 AM, the clock shows 1 AM instead of 2 AM.), what will the following code print?

LocalDateTime ld = LocalDateTime.of(2021, Month.NOVEMBER, 6, 1, 30);
ZonedDateTime date1 = ZonedDateTime.of(ld, ZoneId.of("US/Eastern"));
ZonedDateTime date2 = date1.plusHours(1);
System.out.println( Duration.ofSeconds( date1.getOffset().compareTo(date2.getOffset()))
.toHours() );

You had to select 1 option(s)

1

2

-1

-2

None

Q27. Consider the following array definitions:

int[] array1, array2[];
int[][] array3;
int[] array4[], array5[];
Which of the following are valid statements?

You had to select 3 option(s)

array2 = array3;

array2 = array4;

array1 = array2;

array4 = array1;

array5 = array3;

Q28. Given the following class:

public class SpecialPicker{
public K pickOne(K k1, K k2){
return k1.hashCode()>k2.hashCode()?k1:k2;
}
}
what will be the result of running the following lines of code:

SpecialPicker sp = new SpecialPicker(); //1
System.out.println(sp.pickOne(1, 2).intValue()+1); //2

You had to select 1 option(s)

The first line of code will not compile.

The second line of code will not compile.

It will throw an exception at run time.

It will print 3.

None

Q29. Given:

class Base{
public List transform(List list)
{
return new ArrayList();
}
}

class Derived extends Base{
*INSERT CODE HERE*
}


What can be inserted in the above code?

You had to select 2 option(s)

Q30. Given:

public class Student {
private String name;
private int marks;

//constructor and getters and setters not shown

public void addMarks(int m){
this.marks += m;
}
public void debug(){
System.out.println(name+":"+marks);
}
}

What will the following code print when compiled and run?

List slist = Arrays.asList(new Student("S1", 40),
new Student("S2", 35), new Student("S3", 30));

Consumer increaseMarks = s->s.addMarks(10);
slist.forEach(increaseMarks);
slist.stream().forEach(Student::debug);

You had to select 1 option(s)

S1:50
S2:45
S3:40

S1:40
S2:35
S3:30

It will not print anything.

It will not compile.

None

Q31. Which code fragments will print the last argument given on the command line to the standard output, and exit without any output or exception stack trace if no arguments are given?

1.
public static void main(String args[ ]){
if (args.length != 0) System.out.println(args[args.length-1]);
}

2.
public static void main(String args[ ]){
try { System.out.println(args[args.length-1]); }
catch (ArrayIndexOutOfBoundsException e) { }
}

3.
public static void main(String args[ ]){
int i = args.length;
if (i != 0) System.out.println(args[i-1]);
}

4.
public static void main(String args[ ]){
int i = args.length-1;
if (i > 0) System.out.println(args[i]);
}

5.
public static void main(String args[ ]){
try { System.out.println(args[args.length-1]); }
catch (NullPointerException e) {}
}

You had to select 3 option(s)

1

2

3

4

5

Q32. What will the following code print when compiled and run?

List names = Arrays.asList("charles", "chuk", "cynthia", "cho", "cici");
int x = names.stream().filter(name->name.length()>4).collect(Collectors.counting());
System.out.println(x);

You had to select 1 option(s)

2

3

Exception at run time.

Compilation failure

None

Q33. Which of these array declarations and initializations are NOT legal?

You had to select 2 option(s)

int[ ] i[ ] = { { 1, 2 }, { 1 }, { }, { 1, 2, 3 } } ;

int i[ ] = new int[2] {1, 2} ;

int i[ ][ ] = new int[ ][ ] { {1, 2, 3}, {4, 5, 6} } ;

int i[ ][ ] = { { 1, 2 }, new int[ 2 ] } ;

int i[4] = { 1, 2, 3, 4 } ;

var i = new int[ ][ ] { {1, 2, 3}, {4, 5, 6} } ;

Q34. You are writing a class named Bandwidth for an internet service provider that keeps track of number of bytes consumed by a user. The following code illustrates the expected usage of this class -

class User{
Bandwidth bw = new Bandwidth();

public void consume(int bytesUsed){
bw.addUsage(bytesUsed);
}
... other irrelevant code
}

class Bandwidth{
private int totalUsage;
private double totalBill;
private double costPerByte;


//add your code here

...other irrelevant code
}

Your goal is to implement a method addUsage (and other methods, if required) in Bandwidth class such that all the bandwidth used by a User is reflected by the totalUsage field and totalBill is always equal to totalUsage*costPerByte. Further, that a User should not be able to tamper with the totalBill value and is also not able to reduce it.

Which of the following implementation(s) accomplishes the above?

You had to select 1 option(s)

None

Q35. What is the result of executing the following fragment of code:

var b1 = false;
var b2 = false;
if (b2 = b1 != b2){
System.out.println("true");
} else{
System.out.println("false");
}

You had to select 1 option(s)

Compile time error.

It will print true;

It will print false;

Runtime error.

It will print nothing.

None

Q36. Consider the following code.

import java.time.*;
import java.time.format.*;
public class TestClass
{
public static void main(String[] args) throws Exception
{
LocalDate d = LocalDate.now();
//INSERT CODE HERE
System.out.println(s);
}
}

What should be inserted in the code above so that it will print the date in the following format:

Saturday 1st day of January 2000

You had to select 1 option(s)

DateTimeFormatter dtf = DateTimeFormatter.ofPattern("eeeeeeee d'st day of' MMMMMMM yyyy");
String s = dtf.format(d);

DateTimeFormatter dtf = DateTimeFormatter.ofPattern("eeee d"+"st day of"+ "MMMM yyyy");
String s = dtf.format(d);

DateTimeFormatter dtf = DateTimeFormatter.ofPattern("eee d'st day of' MMM yyyy");
String s = dtf.format(d);

DateTimeFormatter dtf = DateTimeFormatter.ofPattern("eee d\"st day of\" MMM yyyy");
String s = dtf.format(d);

DateTimeFormatter dtf = DateTimeFormatter.ofPattern("eeee d'st day of' MMMM yyyy");
String s = dtf.format(d);

None

Q37. Given :

interface Process{

    public void process(int a, int b);

}

 

public class Data{

    int value;

    Data(int value){

        this.value = value;

    }

}

 

and the following code fragments:

public void processList(ArrayList dataList, Process p){

   for(Data d: dataList){

        p.process(d.value, d.value);

   }

}

 

....

        ArrayList al = new ArrayList();

        al.add(new Data(1));al.add(new Data(2));al.add(new Data(3));

 

        //INSERT METHOD CALL HERE

 

Which of the following options can be inserted above so that it will print 1 4 9?

You had to select 3 option(s)

Q38. Given:

class LowBalanceException extends ______{ //1
public LowBalanceException(String msg){ super(msg); }
}

class WithdrawalException extends ______{ //2
public WithdrawalException(String msg){ super(msg); }
}
class Account{
double balance;
public void withdraw(double amount) {
try{
throw new LowBalanceException("Not Implemented");
}catch(WithdrawalException e){
throw new RuntimeException(e.getMessage());
}
}
public static void main(String[] args) {
try{
Account a = new Account();
a.withdraw(100.0);
}catch(WithdrawalException e){
System.out.println(e.getMessage());
}
catch(Exception e){
System.out.println(e.getMessage());
}
}
}


What can be inserted in the above code at //1 and //2 so that it will print "Not Implemented" when run?

You had to select 1 option(s)

WithdrawalException
Exception

WithdrawalException
RuntimeException

Exception
RuntimeException

RuntimeException
Exception

None

Q39. What will be the result of attempting to compile and run the following code?

public class PromotionTest{
public static void main(String args[]){
int i = 5;
float f = 5.5f;
double d = 3.8;
char c = 'a';
if (i == f) c++;
if (((int) (f + d)) == ((int) f + (int) d)) c += 2;
System.out.println(c);
}
}

You had to select 1 option(s)

The code will fail to compile.

It will print d.

It will print c.

It will print b

It will print a.

None

Q40. A new Java programmer has written the following method that takes an array of ints and sums up all the integers that are less than 100.

public void processArray(int[] values){
int sum = 0;
int i = 0;
try{
while(values[i]<100){
sum = sum +values[i];
i++;
}
}
catch(Exception e){ }
System.out.println("sum = "+sum);
}

Which of the following can be considered a good practice to improve this code?

You had to select 2 option(s)

Use ArrayIndexOutOfBoundsException for the catch argument.

Use ArrayIndexOutOfBoundsException for the catch argument and add code in the catch block to log or print the exception.

Add code in the catch block to handle the exception.

Use flow control to terminate the loop.

Q41. What will be the contents of d at the end of the following code?

Deque d = new ArrayDeque();
d.push(1);
d.offerLast(2);
d.push(3);
d.peekFirst();
d.removeLast();
d.pop();
System.out.println(d);

You had to select 1 option(s)

1

2

3

Exception at run time.

It will not compile.

None

Q42. Given:

class Game{ }
class Cricket extends Game{ }
class Instrument{ }
class Guitar extends Instrument{ }

interface Player{ void play(E e); }
interface GamePlayer extends Player{ }
interface MusicPlayer extends Player{ }

Identify valid declarations.

You had to select 1 option(s)

None

Q43. Consider the following code:

class A{
public XXX m1(int a){
return a*10/4-30;
}
}
class A2 extends A{
public YYY m1(int a){
return a*10/4.0;
}
}

What can be substituted for XXX and YYY so that it can compile without any problems?

You had to select 1 option(s)

int, int

int, double

double, double

double, int

Nothing, they are simply not compatible.

None

Q44. Identity correct statements about the following code:

You had to select 1 option(s)

12345 //order of elements is unpredictable

15342

15314412

Compilation failure

None

Q45. Consider the following program:

public class TestClass{
public static void main(String[] args) {
calculate(2);
}
public static void calculate(int x){
final int TWO = 2;
String val =
switch(x){
case TWO ->
default -> "def";
};
System.out.println(val);
}
}

What will happen if you try to compile and run the program?

You had to select 1 option(s)

It will compile and print def

It will compile and print null

It will generate compilation error saying val may not have been initialized.

It will not compile because case label TWO is neither followed by an expression nor by a code block.

It will not compile because case labels can't use variables, so case TWO is invalid.

None

Q46. What will be the result of attempting to compile and run the following code?

class SwitchTest{
public static void main(String args[]){
for ( var i = 0 ; i < 3 ; i++){ //1
var flag = false;
switch (i){ //2
flag = true; //3
}
if ( flag ) System.out.println( i );
}
}
}

You had to select 1 option(s)

It will print 0, 1 and 2.

It will not print anything.

Runtime error.

Compilation error at line marked //1.

Compilation error at line marked //2.

Compilation error at line marked //3.

None

Q47. What will the following code print?

public class Test{
public static void testInts(Integer obj, int var){
obj = var++;
obj++;
}
public static void main(String[] args) {
Integer val1 = Integer.valueOf(5);
int val2 = 9;
testInts(val1++, ++val2);
System.out.println(val1+" "+val2);
}
}

You had to select 1 option(s)

10 9

10 10

6 9

6 10

5 11

None

Q48. Consider the following code :

Connection connection = dataSource.getConnection();

PreparedStatement stmt = connection.prepareStatement(
"select * from CUSTOMER where EMAILID=?");

stmt.setObject(1, "bob@gmail.com"); //LINE 10

ResultSet rs = stmt.executeQuery();
while(rs.next()){
System.out.println(rs.getString("EMAILID")); //LINE 12
}
connection.close();

Assuming that the query returns exactly 1 row, what will be printed when this code is run?
(Assume that items not specified such as import statements, DB url, and try/catch block are all valid.)

You had to select 1 option(s)

It will throw an exception at //LINE 12.

Compilation will fail due to //Line 12

It will print bob@gmail.com

It will print bob@gmail.com and then throw an exception.

None

Q49. Consider the following code:

public class SubClass extends SuperClass{
int i, j, k;
public SubClass( int m, int n ) { i = m ; j = m ; } //1
public SubClass( int m ) { super(m ); } //2
}

Which of the following constructors MUST exist in SuperClass for SubClass to compile correctly?

You had to select 2 option(s)

It is ok even if no explicit constructor is defined in SuperClass

public SuperClass(int a, int b)

public SuperClass(int a)

public SuperClass()

only public SuperClass(int a) is required.

Q50. Consider the following code snippet:

Connection c = DriverManager.getConnection("jdbc:derby://localhost:1527/sample",
"app", "app");
try(Statement stmt = c.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,
ResultSet.CONCUR_READ_ONLY);)
{
stmt.setMaxRows(5);
ResultSet rs = stmt.executeQuery("""
select customer_id from customer order by customer_id""")
rs.absolute(5);
if(rs.next()){
System.out.println(rs.getString(1));
}

}
catch(SQLException e){
e.printStackTrace();
}


Given that the query returns 5 rows with customer ids ranging from 1 to 5 (in that order), what will the above code print?

You had to select 1 option(s)

5

It will not print anything.

It will print an exception stack trace at runtime.

1

None

Q51. What will the following program print?

public class TestClass{
public static void main(String[] args){
for : for(var i = 0; i< 10; i++){
for (var j = 0; j< 10; j++){
if ( i+ j > 10 ) break for;
}
System.out.println( "hello");
}
}
}

You had to select 1 option(s)

It will print hello 6 times.

It will not compile.

It will print hello 2 times.

It will print hello 5 times.

It will print hello 4 times.

None

Q52. What will happen when the following program is compiled and run?

public class SM{
public String checkIt(String s){
if(s.length() == 0 || s == null){
return "EMPTY";
}
else return "NOT EMPTY";
}

public static void main(String[] args){
SM a = new SM();
System.out.println(a.checkIt(null));
}
}

You had to select 1 option(s)

It will print EMPTY.

It will print NOT EMPTY.

It will throw NullPointerException.

It will print EMPTY if || is replaced with |.

None

Q52. What will the following code print when run?

import java.util.function.*;
class Employee{
int age;
}

public class TestClass{

public static void main(String[] args) {
Employee e = new Employee();
Supplier se = ()->{ e.age = 40; return e; }; //1
e.age = 50;//2
System.out.println(se.get().age); //3
}
}

You had to select 1 option(s)

It will fail to compile at line marked //1

It will fail to compile at line marked //3

No reason for any failure here.

It will print 40.

It will print 50.

It will throw an exception at run time.

None

Q54. Which of the following are benefits of the Java module system?

You had to select 1 option(s)

It saves application developers from Jar hell.

It improves security and maintainability.

It makes it easier to expose implementation details.

It eliminates the need of making custom runtime linked applications.

None

Q55. Given:

enum Coffee
{
ESPRESSO("Very Strong"), MOCHA("Bold"), LATTE("Mild");
public String strength;
Coffee(String strength)
{
this.strength = strength;
}
public String toString(){ return strength; }
}

Which of the given code snippets will produce the following output:
ESPRESSO:Very Strong, MOCHA:Bold, LATTE:Mild,

You had to select 1 option(s)

List.of(Coffee.values()).stream().forEach(e->{System.out.print(e+":"+e.value()+", ");});

List.of(Coffee.values()).stream().forEach(e->{System.out.print(e.name()+":"+e+", ");});

Coffee.values().forEach(e->{System.out.print(e.name()+":"+e+", ");});

List.of(Coffee.values()).forEach(e->{System.out.print(e+":"+e.name()+", ");});

Coffee.forEach(e->{System.out.print(e.strength+":"+e.name()+", ");});

None

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