Java Test 21 – 2024

Q1. Which of the following are valid module definitions?

You had to select 1 option(s)

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)

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)

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)

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)

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)

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

You had to select 1 option(s)

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)

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)

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)

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)

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)

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)

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)

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)

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)

Q17. What will the following command show?

jdeps --list-deps moduleA.jar

You had to select 2 option(s)

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)

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

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)

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)

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)

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)

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)

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)

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)

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)

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)

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)

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)

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)

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

You had to select 2 option(s)

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)

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)

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)

Q37. Given :

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)

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)

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)

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)

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)

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)

Q44. Identity correct statements about the following code:

You had to select 1 option(s)

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)

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)

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)

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)

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)

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)

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)

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)

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)

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

You had to select 1 option(s)

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)