Java Test 23 – 2024

Q1. Given:

public static void generateMultiplicationTable(int number){
Stream sin = Stream.of(1, 2, 3 );
Consumer c1 = System.out::print;
Consumer c2 = x->{ System.out.println(" * "+number+" = "+x*number); };

INSERT CODE HERE
}
public static void main(String[] args) throws Exception{
generateMultiplicationTable(2);
}


Which of the options, when inserted in the above code, will produce the following output:

1 * 2 = 2
2 * 2 = 4
3 * 2 = 6

You had to select 1 option(s)

Q2. Identify correct statements regarding Java module system.

You had to select 1 option(s)

Q3. What will the following code print?

Instant ins = Instant.parse("2022-06-25T16:43:30.00z");
ins.plus(10, ChronoUnit.HOURS);
System.out.println(ins);

You had to select 1 option(s)

Q4. Consider the following code:

import java.util.*;
public class TestClass {
public static void main(String[] args)
{
// put declaration here

m.put("1", new ArrayList()); //1
m.put(1, new Object()); //2
m.put(1.0, "Hello"); //3
System.out.println(m);
}
}

How can 'm' be declared such that the above code will compile and run without errors?

You had to select 2 option(s)

Q5. What will the following code print?

var flag = true;
if(flag = false){
System.out.println("1");
}else if(flag){
System.out.println("2");
}else if(!flag){
System.out.println("3");
}else System.out.println("4");

You had to select 1 option(s)

Q6. Which of the following options correctly add 1 month and 1 day to a given LocalDate -

public LocalDate process(LocalDate ld){
//INSERT CODE HERE
return ld2;
}

You had to select 1 option(s)

Q7. Given:

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

//assume appropriate implementations of equals and hashCode based on isbn property
}

and the following code snippet:

List books = getBooksByAuthor("Ludlum");
books.stream().sorted().forEach(b->System.out.println(b.getIsbn())); //1

Assuming that getBooksByAuthor is a valid method that returns a List of Books, which of the following statements is/are true?

You had to select 1 option(s)

Q8. What can be inserted in the code below so that it will print {a=x, b=xy, c=y}?

Map map1 = new HashMap();
map1.put("a", "x");
map1.put("b", "x");
//INSERT CODE HERE
map1.merge("b", "y", f);
map1.merge("c", "y", f);
System.out.println(map1);

You had to select 1 option(s)

Q9. Which of the following statements will correctly create and initialize an array of Strings to non null elements?

You had to select 4 option(s)

Q10. Which of the following statements are correct regarding synchronization and locks?

You had to select 2 option(s)

Q11. Which of the following statements regarding java.io.File are true?

You had to select 3 option(s)

Q12. What exception will be thrown out of the main method when the following program is run?

package trywithresources;

import java.io.IOException;

public class Device implements AutoCloseable{
String header = null;
public void open() throws IOException{
header = "OPENED";
System.out.println("Device Opened");
throw new IOException("Unknown");
}

public String read() throws IOException{
return "";
}

public void close(){
System.out.println("Closing device");
header = null;
throw new RuntimeException("rte");
}

public static void main(String[] args) throws Exception {
try(Device d = new Device()){
throw new Exception("test");
}
}

}

You had to select 1 option(s)

Q13. Given:

module abc.print{
requires org.pdf;
provides org.pdf.Print with com.abc.print.SimplePrintImpl;
provides org.pdf.Print with com.abc.print.ComplexPrintImpl;
}

Assuming that another module named book uses abc.print module and contains the following code,

ServiceLoader psLoader = ServiceLoader.load(Print.class);
for (Print p : psLoader){
p.print("Hello");
}

identify correct statements.

You had to select 1 option(s)

Q14. Given:

List strList = Arrays.asList("a", "aa", "aaa");
Function f = x->x.length();
Consumer c = x->System.out.print("Len:"+x+" ");
strList.stream().map(f).forEach(c);

What will it print when compiled and run?

You had to select 1 option(s)

Q15. You are trying to compile your module named mycompany.finance. You have put all the source files for your module in src directory. However, your module requires a mycompany.utils module, which is delivered by another team of your company in the form of mycompany.utils.jar file. You have kept this jar in libs directory.

Which of the following commands can be used to compile your module?

You had to select 1 option(s)

Q16. Given:

//using title, price constructor to create Book instances
var books = List.of(new Book("The Outsider", 2.99),
new Book("Where the Crawdads Sing", 4.99 ),
new Book("Elevation", 2.99), new Book("Coffin from Hong Kong", 1.99) );
Stream bkStrm = books.stream();//

double total = bkStrm.map(b->b.getPrice()).reduce(0.0, (a, b)->{ return a+b;}); //1

Assuming appropriate constructor and methods, which of the following options are equivalent to the statement at //1 of the above code?

You had to select 1 option(s)

Q17. Assume that a stored procedure named generateDailyGainsReport exists in your database. It takes two parameters - portfolioId and a date and returns a result set with several rows of data.

Consider the following Java code:

try(Connection c = ds.getConnection();
var stmt = c.prepareCall("{call generateDailyGainsReport(?,?)}") ) { //1
stmt.setObject("PORTFOLIOID", portfolioId, JDBCType.VARCHAR); //2
stmt.setObject("VALUEDATE", date, JDBCType.DATE); //3

boolean hasResult = stmt.execute(); //4
if(hasResult){
ResultSet rs = stmt.getResultSet(); //5
//code to process result
}
}


What will happen when the above code is complied and run?

You had to select 1 option(s)

Q18. What can be inserted at //1 and //2 in the code below so that it can compile without errors:

class Doll{
String name;
Doll(String nm){
this.name = nm;
}
}

class Barbie extends Doll{
Barbie(){
//1
}
Barbie(String nm){
//2
}
}
public class TestClass {
public static void main(String[] args) {
Barbie b = new Barbie("mydoll");
}
}

You had to select 2 option(s)

Q19. Consider the following code appearing in a module-info.java

module com.amazing.movies{ //1
exports com.amazing.movies; //2
exports com.amazing.movies to com.amazing.rentals;//3
requires transitive com.amazing.customer;//4
}

Identify correct statements.

You had to select 1 option(s)

Q20. Which statement(s) 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 class TestClass {

public static void main(String[] args) {
Office off = new HomeOffice(); //2
off.lockTheGates(); //3
House home = (House) off; //4
home.lockTheGates(); //5
}
}

You had to select 1 option(s)

Q21. Consider the following piece of code, which is run in an environment where the default locale is English - US:

Locale.setDefault(new Locale("fr", "CA")); //Set default to French Canada
Locale l = Locale.getDefault();
ResourceBundle rb = ResourceBundle.getBundle("appmessages", l);
String msg = rb.getString("greetings");
System.out.println(msg);

You have created two resource bundles for appmessages, with the following contents:

#In English US resource bundle file
greetings=Hello

#In French CA resource bundle file
greetings=bonjour

What will be the output?

You had to select 1 option(s)

Q22. Which of the following code snippets will print exactly 10?

1. Object t = Integer.valueOf(106);
int k = ((Integer) t).intValue()/10;
System.out.println(k);

2. System.out.println(100/9.9);

3. System.out.println(100/10.0);

4. System.out.println(100/10);

5. System.out.println(3 + 100/10*2-13);

You had to select 3 option(s)

Q23. What will be the output of the following code?

List letters = new ArrayList();
letters.addAll(List.of("a", "c", "b"));

Collections.sort(letters);
System.out.println(Collections.binarySearch(letters, "c"));
Collections.reverse(letters);
System.out.println(Collections.binarySearch(letters, "c"));

You had to select 1 option(s)

Q24. Given the following code fragment, which of the following lines would be a part of the output?

outer:
for ( var i = 0 ; i<3 ; i++ ){
for ( var j = 0 ; j<2 ; j++ ){
if ( i == j ){
continue outer;
}
System.out.println( "i=" + i + " , j=" + j );
}
}

You had to select 2 option(s)

Q25. Consider :

class A {}
class B extends A {}
class C extends B {}

Which of the following boolean expressions correctly identify when the variable o actually refers to an object of class B and not of class C?

You had to select 2 option(s)

Q26. Given the following complete contents of TestClass.java:

import java.util.ArrayList;
import java.util.Collections;

class Address implements Comparable

{
String street;
String zip;
public Address(String street, String zip){
this.street = street; this.zip = zip;
}
public int compareTo(Address o) {
int x = this.zip.compareTo(o.zip);
return x == 0? this.street.compareTo(o.street) : x;
}
}
public class TestClass {
public static void main(String[] args) {
ArrayList

al = new ArrayList();
al.add(new Address("dupont dr", "28217"));
al.add(new Address("sharview cir", "28217"));
al.add(new Address("yorkmont ridge ln", "11223"));
Collections.sort(al);
for(Address a : al) System.out.println(a.street+" "+ a.zip);
}
}

What will be printed?

You had to select 1 option(s)

Q27. You are the maintainer of a library packaged as bondanalytics.jar, which is used by several groups in your company. It has the following two packages that are used by other applications:

com.abc.bonds
com.abc.bonds.analytics

You want to modularize this jar but some groups have not yet modularized their applications. How will such groups use the modularized jar?

You had to select 1 option(s)

Q28. What should be inserted in the following code so that it works as expected?

String token = "xyz";
String output = null;
String processedValueCall = "{call reconciler(?,?)}";
CallableStatement callableStatement = dbConnection.prepareCall(processedValueCall);

*INSERT CODE HERE*

callableStatement.executeUpdate();
String value = callableStatement.getString(2);

Assume that the token variable is the first parameter to be passed.

You had to select 1 option(s)

Q29. Given:

class Book{
private String title;
private double price;
public Book(String title, double price){
this.title = title;
this.price = price;
}
//getters/setters not shown
}

What will the following code print?

List books = Arrays.asList(new Book("Thinking in Java", 30.0),
new Book("Java in 24 hrs", 20.0),
new Book("Java Recipies", 10.0));
double averagePrice = books.stream().filter(b->b.getPrice()>10)
.mapToDouble(b->b.getPrice())
.average().getAsDouble();
System.out.println(averagePrice);

You had to select 1 option(s)

Q30. Which statements about the following code are correct?

interface House{
public default String getAddress(){
return "101 Main Str";
}
}

interface Office {
public static String getAddress(){
return "101 Smart Str";
}
}

interface WFH extends House, Office{
private boolean isOffice(){ return true; }
}

class HomeOffice implements House, Office{
public String getAddress(){
return "R No 1, Home";
}
}

public class TestClass {

public static void main(String[] args) {
Office off = new HomeOffice(); //1
System.out.println(off.getAddress()); //2
}
}

You had to select 1 option(s)

Q31. What will the following code print when compiled and run?

import java.util.*;
public class TestClass {
public static void main(String[] args) throws Exception {
ArrayList al = new ArrayList();
al.add("111");
al.add("222");
System.out.println(al.get(al.size()));
}
}

You had to select 1 option(s)

Q32. Given:

ConcurrentMap cache = new ConcurrentHashMap();
cache.put("111", student1);
(Assume that student1 and student2 are references to a valid objects.)

Which of the following statements are legal but will NOT modify the Map referenced by cache?

You had to select 1 option(s)

Q33. Given:

ConcurrentMap cache = new ConcurrentHashMap();

Which of the given statements are correct about the following code fragment:

if(!cache.containsKey(key)) cache.put(key, value);

(Assume that key and value refer to appropriate objects.)

You had to select 1 option(s)

Q34. Consider the following method...

public void ifTest(boolean flag){
if (flag) //1
if (flag) //2
System.out.println("True False");
else // 3
System.out.println("True True");
else // 4
System.out.println("False False");
}

Which of the following statements are correct ?

You had to select 3 option(s)

Q35. Which of the given statements are correct about the following code?

// Filename: TestClass.java
class TestClass
{
public static void main(String[] args)
{
A a = new A();
B b = new B();
};
}
class A implements T1, T2{}
class B extends A implements T1{}
interface T1 { }
interface T2 { }

You had to select 5 option(s)

Q36. What will the following code print when run?

public class TestClass {
public void switchString(String input){
switch(input){
case "a" : System.out.println( "apple" );
case "b" : System.out.println( "bat" );
break;
case "B" : System.out.println( "big bat" );
default : System.out.println( "none" );
}
}

public static void main(String[] args) throws Exception {
var tc = new TestClass();
tc.switchString("B");
}
}

You had to select 1 option(s)

Q37. What will be the result of compiling and running the following program ?

class NewException extends Exception {}

class AnotherException extends Exception {}

public class ExceptionTest{
public static void main(String[] args) throws Exception{
try{
m2();
}
finally{
m3();
}
catch (NewException e){}
}

public static void m2() throws NewException { throw new NewException(); }

public static void m3() throws AnotherException{ throw new AnotherException(); }

}

You had to select 1 option(s)

Q38. Given the following code, which of the constructors shown in the options can be added to class B without causing a compilation to fail (independent of each other)?

class A{
int i;
public A(int x) { this.i = x; }
}
class B extends A{
int j;
public B(int x, int y) { super(x); this.j = y; }
}

You had to select 2 option(s)

Q39. What will be the output of the following code snippet:

List li = List.of(3, 7, 2, 1, 4, 6, 5, 8);
Spliterator sit1 = li.spliterator();
Spliterator sit2 = sit1.trySplit();
sit1.forEachRemaining(System.out::print);
System.out.println("");
sit2.forEachRemaining(System.out::print);

You had to select 1 option(s)

Q40. What will the following code print when compiled and run?

class Names{
private List list;
public List getList() {
return list;
}
public void setList(List list) {
this.list = list;
}
public void printNames(){
System.out.println(getList());
}

public static void main(String[] args) {
List list = Arrays.asList(
"Bob Hope",
"Bob Dole",
"Bob Brown"
);

Names n = new Names();
n.setList(list.stream().collect(Collectors.toList()));
n.getList().forEach(Names::printNames);
}

}

You had to select 1 option(s)

Q41. Which of the following is a valid module-info for a service provider that provides an Order service defined in OrderServiceAPI module?

You had to select 1 option(s)

Q42. Identify the correct statements about the following code:-

List values = Arrays.asList(2, 4, 6, 9); //1
Predicate check = (Integer i) -> {
System.out.println("Checking");
return i == 4; //2
};
Predicate even = (Integer i)-> i%2==0; //3
values.stream().filter(check).filter(even).count(); //4

You had to select 1 option(s)

Q43. Which of these array declarations and initializations are legal?

You had to select 1 option(s)

Q44. Given the following code:

public String getDateString(LocalDateTime ldt){
return DateTimeFormatter.ISO_ZONED_DATE_TIME.format(ldt);
}

Which of the following statements are correct?

You had to select 1 option(s)

Q45. Given:

class A{
public List getList(){
//valid code
};
}
class B extends A{
@Override
*INSERT CODE HERE*
//valid code
};
}

What can be inserted in the above code?

You had to select 1 option(s)

Q46. Identify the correct statements about the following code:

import java.util.*;
import java.util.function.*;
class Account {
private String id;
public Account(String id){ this.id = id; }
//accessors not shown
}
public class BankAccount extends Account{
private double balance;
public BankAccount(String id, double balance){ super(id); this.balance = balance;}

//accessors not shown

public static void main(String[] args) {
Map myAccts = new HashMap();
myAccts.put("111", new Account("111"));
myAccts.put("222", new BankAccount("111", 200.0));

BiFunction bif =
(a1, a2)-> a2 instanceof BankAccount?new BankAccount(a1, 300.0):new Account(a1); //1

myAccts.computeIfPresent("222", bif);//2
BankAccount ba = (BankAccount) myAccts.get("222");
System.out.println(ba.getBalance());
}
}

You had to select 1 option(s)

Q47. Given:

List ls = Arrays.asList(11, 11, 22, 33, 33, 55, 66);

Which of the following expressions will return true?

You had to select 2 option(s)

Q48. What will be the result of attempting to compile and run the following program?

class TestClass{
public static void main(String args[]){
var b = false;
var i = 1;
do{
i++ ;
} while (b = !b);
System.out.println( i );
}
}

You had to select 1 option(s)

Q49. What will the following code print when compiled and run?

interface Boiler{
public void boil();
private static void log(String msg){ //1
System.out.println(msg);
}
public static void shutdown(){
log("shutting down");
}
}
interface Vaporizer extends Boiler{
public default void vaporize(){
boil();
System.out.println("Vaporized!");
}
}

public class Reactor implements Vaporizer{
public void boil() {
System.out.println("Boiling...");
}

public static void main(String[] args) {
Vaporizer v = new Reactor(); //2
v.vaporize(); //3
v.shutdown(); //4
}
}

You had to select 1 option(s)

Q50. Which of the following are valid JDBC URLs?

You had to select 3 option(s)

Q51. What will be the result of attempting to compile and run the following program?

public class TestClass{
public static void main(String args[]){
Exception e = null;
throw e;
}
}

You had to select 1 option(s)

Q52. Given:

var nums = List.of(1, 2, 3, 4).stream();

Which of the following options will compute the average of the numbers in the nums stream?

You had to select 2 option(s)

Q53. Given the following lines of code:

int rate = 10;
XXX amount = 1 - rate/100*1 - rate/100;

What can XXX be?

You had to select 1 option(s)

Q54. What will the following code print when compiled and run?

List iList = Arrays.asList(1, 2, 3, 4, 5, 6, 7);
Predicate p = x->x%2==0;
List newList = iList.stream().filter(p).filter(x->x>3).collect(Collectors.toList());
System.out.println(newList);

You had to select 1 option(s)

Q55. Given:

sealed interface Member permits Person{ //LINE A
String role();
void role(String role);
}

final class Person implements Member{ //LINE B
private String role = "UNKNOWN";
public String role(){ return role; }
public void role(String role){ this.role = role; }

}

record Student(int id, Person person) //LINE C
{
public String getRole(){ return person.role(); }

public void setRole(String role){ person.role(role); } //LINE D
}

public class TestClass{

public static void main(String[] args) {
Student s = new Student(123, new Person()); //LINE E
s.setRole("student"); //LINE F
System.out.println(s);
}
}



Which lines will cause compilation issues?

You had to select 1 option(s)