Standard Unique Test 4

Q1. What happens when you try to compile and run the following program?

public class CastTest{
public static void main(String args[ ] ){
byte b = -128 ;
int i = b ;
b = (byte) i;
System.out.println(i+" "+b);
}
}

Select 1 option(s):

Q2. Given that the test directory contains two files as described below:

File values1.txt contains:
#13
241
35

File values2.txt contains:
23
#50
12

What will be the output of the following code :

Integer sum = Files.list(Path.of("c:\\temp\\test"))
.flatMap( p -> { try{ return Files.lines(p);
}catch(IOException e){
return null;
} } )
.filter(line -> !line.startsWith("#"))
.map(line -> Integer.parseInt(line.substring(1)))
.reduce((i1, i2)->i1+i2)
.get();
System.out.println(sum);

Select 1 option(s):

Q3. Given:

class A extends Thread
{
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();
a.start();
Thread.sleep(100);
a.interrupt();
}
}

What will be the states of the main thread and the "A" thread created in the above program after the main thread calls a.interrupt()?

Select 1 option(s):

Q4. What should be placed in the two blanks so that the following code will compile without errors:

class XXX{
public void m() {
throw new RuntimeException();
}
}
class YYY extends XXX{
public void m() throws Exception{
throw new Exception();
}
}
public class TestClass {
public static void main(String[] args) {
______ obj = new ______();
obj.m();
}
}

Select 1 option(s):

Q5. Assuming that the following method will always be called with a phone number in the format ddd-ddd-dddd (where d stands for a digit), what can be inserted at //1 so that it will return a String containing "xxx-xxx-"+dddd, where dddd represents the same four digits in the original number?

public static String hidePhone(String fullPhoneNumber){
//1 Insert code here
}

Select 2 option(s):

Q6. Given the following code:

//in WeekDay.java
package days;
public sealed class WeekDay permits Monday {
}

Which of the following is a valid declaration of Monday?

Select 1 option(s):

Q7. Given:

//assume appropriate imports
public class Calculator{
public static void main(String[] args) {
double principle = 100;
int interestrate = 5;
double amount = compute(principle, x->x*interestrate);
}

INSERT CODE HERE
}

Which of the following methods can be inserted in the above code so that it will compile and run without any error/exception?

Select 2 option(s):

Q8. Given:

Locale locale = new Locale("en", "US");
ResourceBundle rb = ResourceBundle.getBundle("test.MyBundle", locale);

Which of the following are valid lines of code?
(Assume that the ResourceBundle has the values for the given keys.)

Select 2 option(s):

Q9. Identify correct statements about the modular system of Java.

Select 3 option(s):

Q10. What will be the result of attempting to compile and run the following class?

public class InitTest{
static String s1 = sM1("a");{
s1 = sM1("b");
}
static{
s1 = sM1("c");
}
public static void main(String args[]){
InitTest it = new InitTest();
}
private static String sM1(String s){
System.out.println(s); return s;
}
}

Select 1 option(s):

Q11. Given:

public static void copy1(Path p1, Path p2) throws Exception {
Files.copy(p1, p2, StandardCopyOption.REPLACE_EXISTING);
}

Identify correct statements.

Select 2 option(s):

Q12. What will the following line of code print?

System.out.println(LocalDate.of(2022, Month.JANUARY, 01)
.format(DateTimeFormatter.ISO_DATE_TIME));

Select 1 option(s):

Q13. Consider the following code:

class Account{
private String id; private double balance;

ReentrantLock lock = new ReentrantLock();

public void withdraw(double amt){
try{
lock.lock();
if(balance > amt) balance = balance - amt;
}finally{
lock.unlock();
}
}
}

What can be done to make the above code thread safe?

Select 1 option(s):

Q14. Given the following code:

package com.auto.vehicles;
public interface Drivable{
void drive();
}

and

package com.auto.vehicles.electric;
public class ECar implements Drivable{
private int maxSpeed;
public ECar(){
this(120);
}
public ECar(int maxSpeed){
this.maxSpeed = maxSpeed;
}

@Override
public void drive(){
System.out.println("driving ecar");
}
}

Which statements should be present in the module-info for it to represent a service provider?

Select 2 option(s):

Q15. Consider the following class...

public class ParamTest {

public static void printSum(double a, double b){
System.out.println("In double "+(a+b));
}

public static void printSum(float a, float b){
System.out.println("In float "+(a+b));
}

public static void main(String[] args) {
printSum(1, 2.0);
printSum(1, 2);
printSum(1.0, 2.0);
}
}

What will be printed?

Select 1 option(s):

Q16. What will the following code print?

String s = "blooper";
StringBuilder sb = new StringBuilder(s);
sb.append(s.substring(4)).delete(3, 5);
System.out.println(sb);

Select 1 option(s):

Q17. Given:

public class CrazyMath {
public static void main(String[] args) {
int x = 10, y = 20;
int dx, dy;
try{
dx = x % 5;
dy = y/dx;
}catch(ArithmeticException ae){
System.out.println("Caught AE");
dx = 2;
dy = y/dx;
}
x = x/dx;
y = y/dy;
System.out.println(dx+" "+dy);
System.out.println(x+" "+y);

}
}

What is the output?

Select 1 option(s):

Q18. Which of the following method implementations will write a boolean value to the underlying stream?

Select 3 option(s):

Q19. What can be done to get the following code to compile and run? (Assume that the options are independent of each other.)

public float parseFloat( String s ){
float f = 0.0f; // 1
try{
f = Float.valueOf( s ).floatValue(); // 2
return f ; // 3
}
catch(NumberFormatException nfe){
f = Float.NaN ; // 4
return f; // 5
}
finally {
return f; // 6
}
return f ; // 7
}

Select 4 option(s):

Q20. Consider the following code:

import java.util.*;
class Book{ }
class TextBook extends Book{ }

class BookList extends ArrayList
{
public int count = 0;
public boolean add(Object o)
{
if(o instanceof Book b) return super.add(b);
else return count++ == -1;
}
}

//in valid context
BookList list = new BookList();
list.add(new Book());
list.add(new TextBook());
list.add("hello");

System.out.println(list.count);

What will it print?

Select 1 option(s):

Q21. The following code was written for Java 7:

Map<String, List> groupedValues = new HashMap();

public void process(String name, Double value){
List values = groupedValues.get(name);
if(values == null){
values = new ArrayList();
groupedValues.put(name, values);
}
values.add(value);
}

Which of the following implementations correctly makes use of the functional interfaces available in the Java standard library to achieve the same?

Select 1 option(s):

Q22. Given:

module broker{
exports org.broker.api;
provides org.broker.api.Broker with org.broker.api.MyBroker
}

Which of the following statements are correct?

Select 3 option(s):

Q23. Consider the following hierarchy of Exception classes :

java.lang.RuntimeException
+----- IndexOutOfBoundsException
+----ArrayIndexOutOfBoundsException, StringIndexOutOfBoundsException

Which of the following statements are correct for a method that can throw ArrayIndexOutOfBounds as well as StringIndexOutOfBounds Exceptions but does not have try catch blocks to catch the same?

Select 3 option(s):

Q24. A modularized application has been packaged in graphs.jar file with module name as com.xcomp.graphs. The entry point of the application is a class named Main in package com.xcomp.graphs.

Which two options can be used to execute this application?

Select 2 option(s):

Q25. Identify correct statements about the following code -

interface Drink{
default double getAlcoholPercent(){
return 0.0;
}

static double computeAlcoholPercent(){
return 0.0;
}
}


interface ColdDrink extends Drink{
String getName();
}

class CrazyDrink implements ColdDrink{
// INSERT CODE HERE
}

Select 1 option(s):

Q26. What will the following code print?

Object v1 = IntStream.rangeClosed(10, 15)
.boxed()
.filter(x->x>12)
.parallel()
.findAny();

Object v2 = IntStream.rangeClosed(10, 15)
.boxed()
.filter(x->x>12)
.sequential()
.findAny();

System.out.println(v1+":"+v2);

(Note: in the options below denote the possible output and not the sign themselves.)

Select 1 option(s):

Q27. Given the following code :

public class TestClass {

int[][] matrix = new int[2][3];

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

public int compute(int x, int y){
//1 : Insert Line of Code here
}

public void loadMatrix(){
for(int x=0; x<matrix.length; x++){
for(int y=0; y<matrix[x].length; y++){
//2: Insert Line of Code here
}
}
}
}

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

Select 1 option(s):

Q28. What will the following code print when run without any arguments ...

public class TestClass {

public static int m1(int i){
return ++i;
}

public static void main(String[] args) {

int k = m1(args.length);
k += 3 + ++k;
System.out.println(k);
}

}

Select 1 option(s):

Q29. What will the following program print?

public class TestClass{
static int someInt = 10;
public static void changeIt(int a){
a = 20;
}
public static void main(String[] args){
changeIt(someInt);
System.out.println(someInt);
}
}

Select 1 option(s):

Q30. Given:

public class ItemProcessor implements Runnable{ //LINE 1
CyclicBarrier cb;
public ItemProcessor(CyclicBarrier cb){
this.cb = cb;
}
public void run(){
System.out.println("processed");
try {
cb.await();
} catch (Exception ex) {
ex.printStackTrace();
}
}
}

public class Merger implements Runnable{ //LINE 2
public void run(){
System.out.println("Value Merged");
}
}

What should be inserted in the following code such that run method of Merger will be executed only after the thread started at 4 and the main thread have both invoked await?

public static void main(String[] args) throws Exception{
var m = new Merger();

//LINE 3

var ip = new ItemProcessor(cb);
ip.start(); //LINE 4
cb.await();
}

Select 1 option(s):

Q31. What will the following code print when run?

String[] sa = { "charlie", "bob", "andy", "dave" };
Collections.sort(Arrays.asList(sa), null);
System.out.println(sa[0]);

Select 1 option(s):

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

public class TestClass {

public static void main(String[] args){
while(var k = 5; k<7){
System.out.println(k++);
}
}
}

Select 1 option(s):

Q33. Given:

int[][] iaa = { {1, 2}, {3, 4}, { 5, 6} };
long count = Stream.of(iaa).flatMapToInt(IntStream::of)
.map(i->i+1).filter(i->i%2 != 0).peek(System.out::print).count();
System.out.println(count);

What will be the output?

Select 1 option(s):

Q34. What will be the result of compiling and running the following code:

float foo = 2, bar = 3, baz = 4; //1
float mod1 = foo % baz, mod2 = baz % foo; //2
float val = mod1>mod2? bar : baz; //3
System.out.println(val);

Select 1 option(s):

Q35. Given the following code:

Locale.setDefault(Locale.ITALY);
Locale loc = new Locale.Builder().setLanguage("en").build();
ResourceBundle rb = ResourceBundle.getBundle("mymsgs", loc);
System.out.println(rb.getString("helloMsg"));

and the following properties files:
mymsgs.properties
mymsgs_en_IT.properties
mymsgs_en.properties
mymsgs_IT.properties

Which of the following statements are correct?

Select 2 option(s):

Q36. Given:

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

and the following code:

List books = List.of(
new Book("Gone with the wind", "Fiction"),
new Book("Bourne Ultimatum", "Thriller"),
new Book("The Client", "Thriller")
);

Reader r = b->{
System.out.println("Reading book "+b.getTitle());
};
books.forEach(x->r.read(x));

What would be a valid definition of Reader for the above code to compile and run without any error or exception?

Select 2 option(s):

Q37. Which of the following code fragments compile without any error?

Select 3 option(s):

Q38. Consider the following code:

class Base{
private float f = 1.0f;
void setF(float f1){ this.f = f1; }
}
class Base2 extends Base{
private float f = 2.0f;
//1
}

Which of the following options is/are valid example(s) of overriding?

Select 2 option(s):

Q39. Given:

Stream strm1 = Stream.of(2, 3, 5, 7, 11, 13, 17, 19); //1
Stream strm2 = strm1.filter(i->{ return i>5 && i<15; }); //2
strm2.forEach(System.out::print); //3

Which of the following options can be used to replace line at //2 and still print the same elements of the stream?

Select 1 option(s):

Q40. Given the following code:

import java.util.Arrays;
import java.util.List;
public class TestClass {
public static void main(String[] args) {
List al = Arrays.asList(100, 200, 230, 291, 43);

System.out.println( *INSERT CODE HERE* );
}
}

Which of the following options will correctly print the number of elements that are less than 200?

Select 1 option(s):

Q41. What will be the output?

var ca = new char[]{'a', 'b', 'c', 'd'};
var i = 0;
for(var c : ca){
switch(c){
case 'a' : i++;
case 'b' : ++i;
case 'c'|'d' : i++;
}
}
System.out.println("i = "+i);

Select 1 option(s):

Q42. What will the following class print when run?

public class Sample{
public static void main(String[] args) {
String s1 = """
java \
java\
""";
StringBuilder s2 = new StringBuilder("news");
s1.replace("java", "");
s2.append(s1);
System.out.println(s2.indexOf("java"));
}
}

Select 1 option(s):

Q43. How will you initialize a DateTimeFormatter object so that the following code will print the number of the month (i.e. 02 for Feb, 12 for Dec, and so on) and a two digit calendar year of any given date?

System.out.println(dtf.format(LocalDate.now()));

Select 1 option(s):

Q44. Which of the following can be valid declarations of an integer variable?

Select 2 option(s):

Q45. Which of the following statements are true?

Select 2 option(s):

Q46. Which of the following implementations of a max() method will correctly return the largest value?

Select 1 option(s):

Q47. Which of the following statements correctly obtains a reference to a Console object?

Select 1 option(s):

Q48. Given:

public class SimpleLoop {
public static void main(String[] args) {
int i=0, j=10;
while (i<=j) {
i++;
j--;
}
System.out.println(i+" "+j);
}
}

What is the result?

Select 1 option(s):

Q49. Given:

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

record Person(String role) implements Member{ //LINE B
}

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

Which lines will cause compilation issues?

Select 1 option(s):

Q50. Given:

class T extends Thread
{
static Lock lock = new ReentrantLock();

public T(String name){ super(name); }

public void run()
{
for(int i=0; i<2; i++){
if(lock.tryLock()){
System.out.println(getName()+" got lock. "+getState());
}else{
System.out.println(getName()+" could not get lock. "+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(1000);
}
}

What is a possible output?

Select 1 option(s):

Q51. What will the following code print?

LongStream ls = LongStream.generate(()->ThreadLocalRandom.current().nextLong()%100);
Long first = ls.sorted().filter(x -> x>-10 && x<10).peek(System.out::println).findFirst().getAsLong();
System.out.println(first);

Select 1 option(s):

Q52.Consider the following code :

String id = c.readLine("%s", "Enter UserId:"); //1
System.out.println("userid is " + id); //2
String pwd = c.readPassword("%s", "Enter Password :"); //3
System.out.println("password is " + pwd); //4

Assuming that c is a valid reference to java.io.Console and that a user types jack as userid and jj123 as password, what will be the output on the console?

Select 1 option(s):

Q53. After which line will the object created at line XXX be eligible for garbage collection?

public Object getObject(Object a) //0
{

Object b = new Object(); //XXX

Object c, d = new Object(); //1
c = b; //2
b = a = null; //3
return c; //4
}

Select 1 option(s):

Q54. Given:

record Point(int x, int y){};
record Line(Point p1, Point p2){}

Which of the following are valid method implementations?

Select 3 option(s):