Standard Unique Test 3

Q1. What will the following program print?

class Test{
public static void main(String[] args){
var i = 4;
int ia[][][] = new int[i][i = 3][i];
System.out.println( ia.length + ", " + ia[0].length+", "+ ia[0][0].length);
}
}

Select 1 option(s):

Q2. 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

Select 1 option(s):

Q3. Identify correct statements regarding Java module system.

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?

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");

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;
}

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?

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);

Select 1 option(s):

Q9. Given:

public class TestClass {
static class Delimiter{
char value = '|';
Delimiter(){
this('-');
}
Delimiter(char ch){
this.value = ch;
}

static{
System.out.print('.');
}

{ System.out.print(value); }

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


}
public static void main(String[] args) {
Delimiter d1 = new Delimiter();
Delimiter d2 = new Delimiter('#');
System.out.println(d1+""+d2);
}
}

What will be the output?

Select 1 option(s):

Q10. Which of the following statements will correctly create and initialize an array of Strings to non null elements?

Select 4 option(s):

Q11. Which of the following statements are correct regarding synchronization and locks?

Select 2 option(s):

Q12. Which of the following statements regarding java.io.File are true?

Select 3 option(s):

Q13. 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");
}
}

}

Select 1 option(s):

Q14. 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.

Select 1 option(s):

Q15. 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?

Select 1 option(s):

Q16. 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?

Select 1 option(s):

Q17. Given:

class MeanTest{
int mean(int i, String s){
return (Integer.parseInt(s)+i)/2;
}
double mean(int i, int j){
return Math.sqrt(i*j);
}
double mean(double i, long j){
return Math.sqrt(i*j);
}
float mean(String s){
return Integer.parseInt(s)/1f;
}
float mean(int i){
return i/1.0f;
}

public static void main(String[] args) {
MeanTest ot = new MeanTest();
var a = "10";
var b = ot.mean(a);

//INSERT CODE HERE

System.out.println(c+" "+d+" "+e);
}
}


Which of the following options when inserted in the above code will produce the output:
10.0 10 10

Select 1 option(s):

Q18. 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?

Select 1 option(s):

Q19. 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");
}
}

Select 2 option(s):

Q20. 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.

Select 1 option(s):

Q21.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?

Select 1 option(s):

Q22. 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?

Select 1 option(s):

Q23. 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);

Select 1 option(s):

Q24. 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
}
}

Select 1 option(s):

Q25. What will the following code print?

Select 1 option(s):

Q26. 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()));
}
}

Select 1 option(s):

Q27. 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?

Select 1 option(s):

Q28. 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.)

Select 1 option(s):

Q29. 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 ?

Select 3 option(s):

Q30. 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 { }

Select 5 option(s):

Q31. 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");
}
}

Select 1 option(s):

Q32. 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(); }

}

Select 1 option(s):

Q33. 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)?

Select 2 option(s):

Q34. 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);

Select 1 option(s):

Q35. 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);
}

}

Select 1 option(s):

Q36. Which of the following is a valid module-info for a service provider that provides an Order service defined in OrderServiceAPI module?

Select 1 option(s):

Q37. 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

Select 1 option(s):

Q38. Which of these array declarations and initializations are legal?

Select 1 option(s):

Q39. Given the following code:

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

Which of the following statements are correct?

Select 1 option(s):

Q40. 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?

Select 1 option(s):

Q41. 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());
}
}

Select 1 option(s):

Q42. Given:

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

Which of the following expressions will return true?

Select 2 option(s):

Q43. 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 );
}
}

Select 1 option(s):

Q44. 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
}
}

Select 1 option(s):

Q45. 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;
}
}

Select 1 option(s):

Q46. 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?

Select 2 option(s):

Q47. Given the following lines of code:

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

What can XXX be?

Select 1 option(s):

Q48. 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);

Select 1 option(s):

Q49. 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?

Select 1 option(s):

Q50. Identify correct statements regarding Java threads.

Select 2 option(s):

Q51. Given:

public class TestClass {
static interface Media{
default void play(){
System.out.println("Media playing");
}
}
static class DvD implements Media{
public void play(){
System.out.println("DvD playing");
}
}
static class CD implements Media{
public void play(){
System.out.println("CD playing");
}
}
static void play(Media m){
m.play();
}
public static void main(String[] args){
Media m1 = new DvD();
DvD d = new DvD();
Media m2 = new CD();
play(m1);
play(d);
play(m2);
}
}

What will be the output?

Select 1 option(s):

Q52. What will the following code fragment print?

ReentrantReadWriteLock rl = new ReentrantReadWriteLock();
Lock rlock = rl.readLock();
Lock wlock = rl.writeLock();
String result = "default ";
try{
rlock.lock();
result = result+"1 ";
if(wlock.tryLock()){
result = result+"2 ";
}else{
rlock.lock();
result = result+"3 ";
}
}catch(Exception e){
result = result+"4 ";

}finally{
rlock.unlock();
result = result+rl.getReadHoldCount()+" "+rl.isWriteLocked();
}
System.out.println(result);

Select 1 option(s):

Q53. Which statements regarding the following code are correct?

class A implements Runnable
{
public void run()
{
System.out.println("Starting loop");
try{
Thread.sleep(10000); //1 sleep for 10 secs
}catch(Exception e){ e.printStackTrace(); }
System.out.println("Ending loop");
}
}
public class TestClass
{
public static void main(String args[]) throws Exception
{
A a = new A();
Thread t = Thread.startVirtualThread(a);
Thread.sleep(1000);
t.interrupt();
}
}

Select 2 option(s):

Q54. Given:

public class TestClass2 {
static ArrayList al = new ArrayList();
public static void main(String[] args) {
Runnable r = ()->{
for(int i=0; i<5000; i++){
synchronized (al) {
al.add(i);
}
}
};
Thread t1 = new Thread(r, "T1");
Thread t2 = new Thread(r, "T2");

ExecutorService es = Executors.newFixedThreadPool(2);
Future f1 = es.submit(t1);
Future f2 = es.submit(t2);
es.shutdown();
try{
f1.get();
f2.get();
System.out.println(al);
}catch(Exception e){
e.printStackTrace();
}
}
}

What is the result?

Select 1 option(s):