Standard Unique Test 2

Q1. What will the following code print when compiled and run?

record Student(int id, String... subjects) {
public Student{
if(id<0) throw new IllegalArgumentException();

if( subjects == null || subjects.length == 0) {
subjects = new String[] {"english" };
}
}
}

public class TestClass{

public static void main(String[] args) {
Student s = new Student(123, null);
switch(s){
case Student(var id, var subjects) : System.out.println(s);
default : System.out.println("default");
}
}
}

Select 1 option(s):

Q2. 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("aa", "aaa", "b", "cc", "ccc", "ddd", "a");
//INSERT CODE HERE
System.out.println(count);
}
}

Which of the following options will correctly print the number of elements that will come before the string "c" if the list were sorted alphabetically?

Select 1 option(s):

Q3. 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){
System.out.print("Media: ");
m.play();
}
static void play(DvD d){
System.out.print("DvD: ");
d.play();
}
public static void main(String[] args){
Media m = new DvD();
DvD d = new DvD();
CD c = new CD();
play(m);
play(d);
play(c);
}
}

What will be the output?

Select 1 option(s):

Q4. Given the following code for Book class:

record Book(String title, String isbn){
//insert code here
}

What of the following options illustrates correct usage of instanceof with pattern matching?

Select 2 option(s):

Q5. Which of the following code snippets will print a String containing exactly 100 characters?

Select 2 option(s):

Q6. Given:

public class TestClass {
static interface Media{
default void play(){
System.out.println("Media playing");
}
}
static class ROM implements Media{
public void play(){
System.out.println("ROM playing");
}
}
static class CdROM extends ROM implements Media{
}

static void play(Media m){
System.out.print("Media: ");
m.play();
}
static void play(CdROM d){
System.out.print("CdROM: ");
d.play();
}

public static void main(String[] args){
ROM r1 = new ROM();
Media r2 = new CdROM();
play(r1);
play(r2);
}
}

What will be the output?

Select 1 option(s):

Q7. Consider the following code :

public class TestClass extends Thread
{
class Runner implements Runnable
{
public void run()
{
var t = new Thread[5];
for(int i=0; i<t.length; i++) System.out.println(t[i]);
}
}

public static void main(String args[]) throws Exception
{
var tc = new TestClass();
new Thread( tc.new Runner() ).start();
}
}

How many Thread objects are created by the above program when it is compiled and run?

Select 1 option(s):

Q8. Consider the following code:

class A {
public void doA(int k) throws Exception { // 0
for(int i=0; i< 10; i++) {
if(i == k) throw new Exception("Index of k is "+i); // 1
}
}
public void doB(boolean f) { // 2
if(f) {
doA(15); // 3
}
else return;
}
public static void main(String[] args) { // 4
A a = new A();
a.doB(args.length>0); // 5
}
}

Which of the following statements are correct?

Select 1 option(s):

Q9. Given that Book is a valid class with appropriate constructor and getPrice method that returns a double, what can be inserted at //1 so that it will sum the price of all the books that are priced greater than 5.0?

List books = Arrays.asList(
new Book("Gone with the wind", 10.0),
new Book("Atlas Shrugged", 10.0),
new Book("Freedom at Midnight", 5.0),
new Book("Gone with the wind", 5.0)
);

//1 INSERT CODE HERE

System.out.println(sum);

Select 2 option(s):

Q10. What will the following code print?

public class Test{
public int luckyNumber(int seed){
if(seed > 10) return seed%10;
int x = 0;
try{
if(seed%2 == 0) throw new Exception("No Even no.");
else return x;
}
catch(Exception e){
return 3;
}
finally{
return 7;
}
}

public static void main(String args[]){
int amount = 100, seed = 6;
switch( new Test().luckyNumber(6) ){
case 3: amount = amount * 2;
case 7: amount = amount * 2;
case 6: amount = amount + amount;
default :
}
System.out.println(amount);
}
}

Select 1 option(s):

Q11. Which of the given lines can be inserted at //1 of the following program ?

public class TestClass
{
public static void main(String[] args)
{
short s = 9;
//1
}

}

Select 2 option(s):

Q12. What, if anything, is wrong with the following code?

interface T1{
}
interface T2{
int VALUE = 10;
void m1();
}

interface T3 extends T1, T2{
public void m1();
public void m1(int x);
}

Select 1 option(s):

Q13. Consider the following code:

class A
{
}
public class TestClass
{
public class A
{
public void m() { }
}
class B extends A
{
B(){ m(); }
}
public static void main(String args[])
{
new TestClass().new A() { public void m() { } }; //1
var tc = new TestClass();
//insert call to A's m() here
}
}

Select 4 option(s):

Q14. What will the following code NEVER print when run?

enum SIZE
{
TALL, JUMBO, GRANDE;
}

class CoffeeMug
{

public static void main(String[] args)
{
var hs = new HashSet();
hs.add(SIZE.TALL); hs.add(SIZE.JUMBO); hs.add(SIZE.GRANDE);
hs.add(SIZE.TALL); hs.add(SIZE.TALL); hs.add(SIZE.JUMBO);
for(SIZE s : hs) System.out.print(s+" ");
}
}

Select 2 option(s):

Q15. Given:

public class Book{
private String title;
private Double price;
public Book(String title, Double price){
this.title = title;
this.price = price;
}
//accessor methods not shown

What will the following code print when compiled and run?

Book b1 = new Book("Java in 24 hrs", null);
DoubleSupplier ds1 = b1::getPrice;
System.out.println(b1.getTitle()+" "+ds1.getAsDouble());

Select 1 option(s):

Q16. Given:

module broker{
exports org.broker.api;
}

The broker module contains org.broker.api.Installer interface, which is implemented by com.foo.AppInstaller class of com.foo module.

Which of the following is a valid module definition for com.foo module?

Select 1 option(s):

Q17. The following are complete contents of TestClass.java:

class Book{
protected final int pages = 100;
final void mA(){
System.out.println("In B.mA "+pages);
}
}

class Encyclopedia extends Book{
private int pages = 200; //1
void mB(){
System.out.println("In E.mB "+pages);
}
void mA(){ //2
System.out.println("In E.mA "+pages);
}
}
public class TestClass {
public static void main(String[] args) {
Book o1 = new Encyclopedia (); //3
Book o2 = new Book();
o1.mA(); //4
o1.mB(); //5
o2.mA();
}
}

Which lines will cause compilation to fail?

Select 1 option(s):

Q18. Given:

int expr1 = 3 + 5 * 9 - 7;
int expr2 = 3 + (5 * 9) - 7;
int expr3 = 3 + 5 * (9 - 7);
int expr4 = (3 + 5) * 9 - 7;

Which of the above variables will have the value 45?

Select 1 option(s):

Q19. Given the following command:

javac --module-source-path c:\java\a -d c:\java\b -p c:\java\c -m x.y

Which of the following statements are correct?

Select 1 option(s):

Q20. Given:

public class Triangle{
public int base;
public int height;
public double area;

public Triangle(int base, int height){
this.base = base; this.height = height;
updateArea();
}

void updateArea(){
area = base*height/2;
}
public void setBase(int b){ base = b; updateArea(); }
public void setHeight(int h){ height = h; updateArea(); }
}
The above class needs to protect an invariant on the "area" field (meaning, the value of the ///area/// field should always be equal to the value computed using the formula for area of a triangle). Which three members must have the public access modifiers removed to ensure that the invariant is maintained?

Select 3 option(s):

Q21. What will the following code print?

int[] a = { 'h', 'e', 'l'};
int[] b = { 'h', 'e', 'l', 'l', 'o'};

int x = Arrays.compare(a, b);
int y = Arrays.mismatch(a, b);
System.out.println(x+" "+y);

Select 1 option(s):

Q22. What will the following code print when compiled and run?

public class TestClass {
public static void main(String[] args) {

String s = "blooper";
StringBuilder sb = new StringBuilder(s);
s.append("whopper");
sb.append("shopper");

System.out.println(s);
System.out.println(sb);
}
}

Select 1 option(s):

Q23. Identify correct statement(s) about the following code:

var value = 1,000,000; //1
switch(value){
case 1_000_000 -> { //2
System.out.println("A million 1");
break; //3
}
case 1000000 -> { //4
System.out.println("A million 2");
}
}

Select 1 option(s):

Q24. Consider the following code:

public class FileCopier {
public static void copy(String records1, String records2) throws IOException {
try (
InputStream is = new FileInputStream(records1);
OutputStream os = new FileOutputStream(records2);) {
byte[] buffer = new byte[1024];
int bytesRead = 0;
while ((bytesRead = is.read(buffer)) != -1) {
os.write(buffer, 0, bytesRead);
System.out.println("Read and written bytes " + bytesRead);
}
} catch (IOException | IndexOutOfBoundsException e) {
e = new FileNotFoundException();
e.printStackTrace();
}
}

public static void main(String[] args) throws Exception {
copy("c:\\temp\\test1.txt", "c:\\temp\\test2.txt");
}
}

Assuming appropriate import statements and the existence of both the files, what will happen when the program is compiled and run?

Select 1 option(s):

Q25. What will the following code print when run?

public class Test{
static String j = "";
public static void method( int i){
try{
if(i == 2){
throw new Exception();
}
j += "1";
}
catch (Exception e){
j += "2";
return;
}
finally{
j += "3";
}
j += "4";
}
public static void main(String args[]){
method(1);
method(2);
System.out.println(j);
}
}

Select 1 option(s):

Q26. Which of the following approaches are good to perform thread safe iteration of elements of a collection?

Select 1 option(s):

Q27. What will the following code print?

Path p1 = Paths.get("/photos/vacation");
Path p2 = Paths.get("/yellowstone");
System.out.println(p1.resolve(p2)+" "+p1.relativize(p2));

Select 1 option(s):

Q28. Given the following class, which statements can be inserted at line 1 without causing the code to fail compilation?

public class TestClass{
int a;
int b = 0;
static int c;
public void m(){
int d;
int e = 0;
// Line 1
}
}

Select 4 option(s):

Q29.Given:

List dList = Arrays.asList(10.0, 12.0);
dList.forEach(x->{ x = x + 10; });
dList.forEach(x->System.out.println(x));

What will it print when compiled and run?

Select 1 option(s):

Q30. Given the following method code:

public void myMethod() throws MyException {

//method code

}

Select 1 option(s):

Q31. Which of the following commands can be used to run a class named com.foo.Bar, which is part of a module named foo.bar packaged in foobar.jar

(Assume that the jar file is located in the current directory.)

Select 1 option(s):

Q32. Which of these are valid expressions to create a string of value "hello world" ?

Select 3 option(s):

Q33. What will the following code print when compiled and run?

(Assume that MySpecialException is an unchecked exception.)

1. public class ExceptionTest {
2. public static void main(String[] args) {
3. try {
4. doSomething();
5. } catch (MySpecialException e) {
6. System.out.println(e);
7. }
8. }
9.
10. static void doSomething() {
11. int[] array = new int[4];
12. array[4] = 4;
13. doSomethingElse();
14. }
15.
16. static void doSomethingElse() {
17. throw new MySpecialException("Sorry, can't do something else");
18. }
}

Select 1 option(s):

Q34. What will the following code print?

List str = Arrays.asList(1,2, 3, 4 );
str.stream().filter(x->{
System.out.print(x+" ");
return x>2;
});

Select 1 option(s):

Q35. The following code snippet will print true.

String str1 = "one";
String str2 = "two";
System.out.println( str1.equals(str1=str2) );

Select 1 option(s):

Q36. Given:

public class Book {
private int id;
private String title;
private String genre;
private String author;
private double price;

//constructors and accessors not shown
}

Assuming that books is a List of Book objects, what can be inserted in the code below at DECLARATION and EXPRESSION so that it will classify the books by genre and then also by author?

DECLARATION classified = null;
classified = books.stream().collect(Collectors.groupingBy(
EXPRESSION
));
System.out.println(classified);

Select 1 option(s):

Q37. Given:

StringBuilder sb = new StringBuilder("asdf");

Which of the following code fragments will print true?

Select 1 option(s):

Q38. Given:

class OverloadingTest{

void m1(int x){
System.out.println("m1 int");
}

void m1(float x){
System.out.println("m1 float");
}

void m1(String x){
System.out.println("m1 String");
}

}

public class TestClass {
public static void main(String[] args) throws Exception {
OverloadingTest ot = new OverloadingTest();
ot.m1(1.0);
}
}

What will be the output?

Select 1 option(s):

Q39. Consider the following

public class TestClass {
public static void main(String[] args) {
TestClass tc = new TestClass();
tc.myMethod();
}

public void myMethod() {
yourMethod();
}

public void yourMethod() {
throw new Exception();
}
}

What changes can be done to make the above code compile?

Select 1 option(s):

Q40. 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(); }
}
public static void m2() throws NewException{ throw new NewException(); }
public static void m3() throws AnotherException{ throw new AnotherException(); }
}

Select 1 option(s):

Q41. Given:

abstract class Vehicle{ }
interface Drivable{ }
class Car extends Vehicle implements Drivable{ }
class SUV extends Car { }

Which of the following options will compile?

Select 2 option(s):

Q42. What will the following code most likely print when compiled and run?

List names = Arrays.asList("greg", "dave", "don", "ed", "fred" );
Map data = names.stream().collect(Collectors.groupingBy(
String::length,
Collectors.counting()) );
System.out.println(data.values());

Select 1 option(s):

Q43. Assume that dt refers to a valid java.util.Date object and that df is a reference variable of class DateFormat.

Which of the following code fragments will print the country and the date in the correct local format?

Select 1 option(s):

Q44. Given that c:\temp\pathtest is a directory that contains several directories. Each sub directory contains several files but there is exactly one regular file named test.txt within the whole directory structure.

Which of the given options can be inserted in the code below so that it will print complete path of test.txt?

try{
Stream s = null;

INSERT CODE HERE

s.forEach(System.out::println);
}catch(IOException ioe){
ioe.printStackTrace();
}

Select 1 option(s):

Q45. Given the following source code, which of the lines that are commented out may be reinserted without introducing errors?

abstract class Bang{
// abstract void f(); // LINE 0
final void g(){}
// final void h(){} // LINE 1
protected static int i;
private int j;
}

final class BigBang extends Bang{
// BigBang(int n) { m = n; } // LINE 2
public static void main(String args[]){
Bang mc = new BigBang();
}
// @Override // LINE 3
void h(){}
// void k(){ i++; } // LINE 4
// void l(){ j++; } // LINE 5
int m;
}

Consider each line independently.

Select 1 option(s):

Q46. Given that listOfWords points to a List of words, which of the following code snippets will create a list of two letter words?

Select 3 option(s):

Q47. 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 = Arrays.asList(
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):

Q48. Given:

public static void main(String[] args) {
String str = "10";
int iVal = 0;
Double dVal = 0.0;
try{
iVal = Integer.parseInt(str, 2); //1
if((dVal = Double.parseDouble(str)) == iVal){ //2
System.out.println("Equal");
}
}catch(NumberFormatException e){
System.out.println("Exception in parsing");
}
System.out.println(iVal+" "+dVal);

}

What is the result?

Select 1 option(s):

Q49. Identify the right declaration for 'box' for the following code.

import java.util.*;
class Dumper {
// declaration for box

public void dumpStuff(){
for(List l : box.values()){
System.out.println(l);
}
}
}

Select 2 option(s):

Q50. What will the following program print when run?

// Filename: TestClass.java
public class TestClass{
public static void main(String args[] ){ A b = new B("good bye"); }
}
class A{
A() { this("hello", " world"); }
A(String s) { System.out.println(s); }
A(String s1, String s2){ this(s1 + s2); }
}
class B extends A{
B(){ super("good bye"); };
B(String s){ super(s, " world"); }
B(String s1, String s2){ this(s1 + s2 + " ! "); }
}

Select 1 option(s):

Q51. Given that daylight Savings Time starts on March 13th, 2022 at 2 AM in US/Eastern time zone. (As a result, 2 AM becomes 3 AM. In other words, 1 minute after 1.59AM, the clock goes to 3.00 AM instead of 2 AM), what will the following code print?

LocalDateTime ld1 = LocalDateTime.of(2022, Month.MARCH, 13, 2, 0);
ZonedDateTime zd1 = ZonedDateTime.of(ld1, ZoneId.of("US/Eastern"));
LocalDateTime ld2 = LocalDateTime.of(2022, Month.MARCH, 13, 3, 0);
ZonedDateTime zd2 = ZonedDateTime.of(ld2, ZoneId.of("US/Eastern"));
long x = ChronoUnit.HOURS.between(zd1, zd2);
System.out.println(x);

Select 1 option(s):

Q52. Given that New York is 3 hours ahead of Los Angeles, what will the following code print?

LocalDateTime ldt = LocalDateTime.of(2022, 12, 02, 6, 0, 0);
ZonedDateTime nyZdt = ldt.atZone(nyZone);
ZonedDateTime laZdt = ldt.atZone(laZone);
Duration d = Duration.between(nyZdt, laZdt);
System.out.println(d);

Select 1 option(s):

Q53. What will be the output when the following code is compiled and run?

class Person implements Serializable{
private String name;
Person(String name){
this.name = name;
System.out.print("Person ");
}
public String toString(){ return name; }
}

class Student extends Person{
public String school;
public Student(String name, String school){
super(name);
this.school = school;
System.out.print("Student ");
}
public String toString(){
return super.toString()+" "+school;
}
}
public class SerialTest {
public static void main(String[] args) throws Exception {
Person p = new Student("Bob Dylan", "NYU");
try(
ObjectOutputStream oos = new ObjectOutputStream(
new FileOutputStream("c:\\temp\\student.ser"));

ObjectInputStream ois = new ObjectInputStream(
new FileInputStream("c:\\temp\\student.ser"));
){
oos.writeObject(p);
oos.flush();
System.out.println((Person)ois.readObject());
}
}
}

Select 1 option(s):

Q54. Given:

class InternalException extends RuntimeException {
public InternalException(String message) {
super (message);
}
}

class ExternalException extends Exception{
public ExternalException (String message) {
super (message);
}
}
class MicroService implements AutoCloseable{
private String name;
public MicroService(String name){
this.name = name;
System.out.println(name+" started");
}
public void availService(String name) {
if (!this.name.equals(name)) {
throw new InternalException ("Unknown service "+name);
}
}

@Override
public void close() throws ExternalException {
if (name.equals("X")) {
throw new ExternalException("Can't close X service");
}
System.out.println(name+" closed");
}

public static void main(String[] args) {
try(MicroService ms = new MicroService("X")){
ms.availService("test");
}
catch(Exception e){
System.out.println(e);
}
}
}

What will be the result?

Select 1 option(s):