Java Test 13 – 2024

Q1. What will the following code print?

public class Test{
public static void stringTest(String s){
s.replace("h", "s");
}
public static void stringBuilderTest(StringBuilder s){
s.append("o");
}
public static void main(String[] args){
String s = "hell";
StringBuilder sb = new StringBuilder("well");
stringTest(s);
stringBuilderTest(sb);
System.out.println(s + sb);
}
}

You had to select 1 option(s)

Q2. What will be the output when the following program is run?

public class TestClass{
char c;
public void m1(){
char[ ] cA = { 'a' , 'b'};
m2(c, cA);
System.out.println( ( (int)c) + "," + cA[1] );
}
public void m2(char c, char[ ] cA){
c = 'b';
cA[1] = cA[0] = 'm';
}
public static void main(String args[]){
new TestClass().m1();
}
}

You had to select 1 option(s)

Q3. Which of the following are valid code snippets appearing in a method:

You had to select 3 option(s)

Q4. What will the following code print when compiled and run?

List values = Arrays.asList("Java EE", "C#", "Python");
boolean flag = values.stream().allMatch(str->{
System.out.println("Testing: "+str);
return str.equals("Java");
});
System.out.println(flag);

You had to select 1 option(s)

Q5. Which of the following lines will cause the compilation to fail?

interface I { }

public enum EnumA implements I, Serializable { A, AA, AAA}; //1


class TestClass
{
public enum EnumB{ B, BB, BBB;
public Object clone(){ return B; } //2
}

public static enum EnumC{ C, CC, CCC };

public static enum EnumD extends EnumC{ DDD }; //3

public TestClass()
{
System.out.println(EnumC.CC.index()); //4
}


public static void main(String[] args)
{
System.out.println(EnumC.valueOf("ccc")); //5
System.out.println(EnumC.CCC.name()); //6
System.out.println(EnumC.CCC.ordinal()); //7
}
}

You had to select 3 option(s)

Q6. Given:

class Buddy {
public Buddy(){ }
}
public class GCTest
public static void initBuddies(Buddy[] ba){
ba[0] = new Buddy(); //1
ba[1] = new Buddy(); //2
ba[0] = ba[1]; //3
ba[1] = ba[2]; //4
}

public static void main(String[] args) {
Buddy[] ba = new Buddy[3]; //5
initBuddies(ba); //6

//7

}
}

How many Buddy objects will be eligible for garbage collection at line marked //7?

You had to select 1 option(s)

Q7. Which of the following illustrates a good coding practice given that the database connection is to be reused?

You had to select 1 option(s)

Q8. Which of the following are correct ways to initialize the static variables MAX and CLASS_GUID ?

class Widget{
static int MAX; //1
static final String CLASS_GUID; // 2
Widget(){
//3
}
Widget(int k){
//4
}
}

You had to select 2 option(s)

Q9. Your application consists of two jar files produced by two different teams - accounting-3.2.jar and reporting-5.6.jar. Classes in reporting-5.6.jar use the class com.abc.account.Account in accounting-3.2.jar while classes in accounting-3.2.jar do not refer to classes from reporting-5.6.jar.

The accounting team has decided to modularize their jar. Which of the following would be a valid module-info.java for the new accounting-3.3.jar?

You had to select 1 option(s)

Q10. Consider the following piece of code:

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

You have created two resource bundle files with the following contents:

#In appmessages.properties:
greetings=Hello

#In appmessages_fr_FR.properties:
greetings=bonjour

Given that this code is run on machines all over the world. Which of the following statements are correct?

You had to select 1 option(s)

Q11. Given the following module definitions:

module m${
requires _n;
exports o;
}

module _n{
requires m$;
exports p;
}

Identify the correct statements.

You had to select 1 option(s)

Q12. What will the following code print?

public static void main(String[] args) {
Integer x = 3;
switch(x){
case 1, 2 -> System.out.println("A");
case 3, 4 -> System.out.println("B");
default -> System.out.println("C");
}
}

You had to select 1 option(s)

Q13. Given a class named Test, which of these would be valid definitions for a constructor for the class?

You had to select 1 option(s)

Q14. Given:

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

Which of the following options correctly achieves the same or compatible declaration using type inference?

You had to select 2 option(s)

Q15. Which of the statements regarding the given code are correct?

public class Test extends Thread
{
static Object obj1 = new Object();
static Object obj2 = new Object();
public void m1()
{
synchronized(obj1)
{
System.out.print("1 ");
synchronized(obj2)
{
System.out.println("2");
}
}
}
public void m2()
{
synchronized(obj2)
{
System.out.print("2 ");
synchronized(obj1)
{
System.out.println("1");
}
}
}
public void run()
{
m1();
m2();
}
public static void main(String[] args)
{
new Test().start();
new Test().start();
}
}

You had to select 1 option(s)

Q16. What will the following code print when compiled and run?

interface Eatable{
int types = 10;
}
class Food implements Eatable {
public static int types = 20;
}
public class Fruit extends Food implements Eatable{ //LINE1

public static void main(String[] args) {
types = 30; //LINE 2
System.out.println(types); //LINE 3
}
}

You had to select 1 option(s)

Q17. Consider the following code:

interface Classic {
int version = 1;
public void read() ;
}

class MediaReader implements Classic{
int version = 2;
public void read() {

//Insert code here

}
}

public class ReaderTest{
public static void main(String[] args) {
MediaReader mr = new MediaReader();
mr.read();
}
}


What can be inserted in the code above so that it will print 1 when run?

You had to select 1 option(s)

Q18. Given:

public class TestClass {
public void myMethod(String... params) {
var a = params;
var b = params[0];
}
}

What are the types of the variables a and b?

You had to select 1 option(s)

Q19. What will the following code print when run?

public class TestClass
{
public static void main(String args[])
{
A a = new B();
if( a instanceof B b){
b.b();
}
System.out.println(b);

}
}
class A {
void a(){ System.out.println("a"); }
}
class B extends A {
void b(){ System.out.println("b"); }
}

You had to select 1 option(s)

Q20. Identify correct statements about Java platform module system.

You had to select 2 option(s)

Q21. Which of the following classes have a default constructor?

class A{ }
class B { B(){ } }
class C{ C(String s){ } }

You had to select 1 option(s)

Q22. You want to print the date that represents upcoming Tuesday from now even if the current day is a Tuesday. Which of the following lines of code accomplishe(s) this?

You had to select 2 option(s)

Q23. Identify the correct statements about ArrayList?

You had to select 3 option(s)

Q24. Which of the following lines of code that, when inserted at line 1, will make the overriding method in SubClass invoke the overridden method in BaseClass on the current object with the same parameter.

class BaseClass{
public void print(String s) { System.out.println("BaseClass :"+s); }
}
class SubClass extends BaseClass{
public void print(String s){
System.out.println("SubClass :"+s);
// Line 1
}
public static void main(String args[]){
SubClass sc = new SubClass();
sc.print("location");
}
}

You had to select 1 option(s)

Q25. Consider the directory structure and its contents shown in the figure.

(c:\temp is a directory that contains two text files - test1.txt and text2.txt)

What should be inserted at //LINE 10 in the following code so that it will write "hello" to text2.txt?

public static void writeData() throws Exception{
var p1 = Paths.get("c:\\temp\\test1.txt");
var p2 = //LINE 10 - INSERT CODE HERE
var bw = new BufferedWriter(new FileWriter(p2.toFile()));
bw.write("hello");
bw.close();
}

You had to select 1 option(s)

Q26. What will the following code print when compiled and run?

var numA = new Integer[]{1, 2};
var list1 = List.of(numA);
numA[0] = 2;
var list2 = List.copyOf(list1);
System.out.println(list1+" "+list2);

You had to select 1 option(s)

Q27. Given that the user account under which the following code is run does not have the permission to access a.java, what will the the following code print when run?

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.nio.file.AccessDeniedException;
import java.nio.file.NoSuchFileException;

public class IOTest {
public static void main(String[] args) {
try(BufferedReader bfr = new BufferedReader(
new FileReader("c:\\works\\a.java"))){
String line = null;
while( (line = bfr.readLine()) != null){
System.out.println(line);
}
}catch(NoSuchFileException|IOException|AccessDeniedException e){
e.printStackTrace();
}
}
}

You had to select 1 option(s)

Q28. Given:

abstract class AmazingClass{
void amazingMethod(Collection c){
System.out.println("Got collection");
};
}

public class SpecialAmazingClass extends AmazingClass{
void amazingMethod(List l){
System.out.println("Got list");
};

public static void main(String[] args) {
List al = new ArrayList();
Collection c = al;
AmazingClass ac = new SpecialAmazingClass();
ac.amazingMethod(c);
}
}

What is the output?

You had to select 1 option(s)

Q29. Given:

String s1 = "Hello World";
String s2 = """
Hello World""";
String s3 = """
Hello World
""";
System.out.println((s1 == s2)+" "+s2.equals(s3)+" "+s2.intern().equals(s3.intern()));

What is the result?

You had to select 1 option(s)

Q30. Consider the following code:

class A
{
byte getStatusCode(Object obj) throws NullPointerException
{
if(obj != null ) return 128;
else return -1;
}
}
class B extends A
{
//override getStatusCode method.
}

Which of the following statements are valid?

You had to select 3 option(s)

Q31. What letters will be printed by this program?

public class ForSwitch{
public static void main(String args[]){
char i;
LOOP: for (i=0;i<5;i++){
switch(i++){
case '0': System.out.println("A");
case 1: System.out.println("B"); break LOOP;
case 2: System.out.println("C"); break;
case 3: System.out.println("D"); break;
case 4: System.out.println("E");
case 'E' : System.out.println("F");
}
}
}
}

You had to select 2 option(s)

Q32. Which of the following are valid method implementations?

You had to select 2 option(s)

Q33. What will the following code print when run?

import java.nio.file.Path;
import java.nio.file.Paths;

public class PathTest {
static Path p1 = Paths.get("c:\\finance\\data\\reports\\daily\\pnl.txt");

public static void main(String[] args) {
System.out.println(p1.subpath(0, 2));
}
}

You had to select 1 option(s)

Q34. Given:

Path p = Paths.get("c:\\temp\\out");
try{
var b = Files.deleteIfExists(p);
System.out.println(b);
}catch(Exception e){
e.printStackTrace();
}

Identify correct statements.

You had to select 1 option(s)

Q35. What will the following code print when compiled and run?

List countries = List.of("US", "UK", "India", "Argentina");
List capitals = List.of("Washington DC", "London", "New Delhi" );
Stream is = IntStream
.range(0, Math.min(countries.size(), capitals.size()))
.mapToObj(i->countries.get(i)+" "+capitals.get(i));
is.forEach(System.out::println);

You had to select 1 option(s)

Q36. Consider the following two classes (in the same package but defined in different source files):

public class Square {
double side = 0;
double area;

public Square(double length){ this.side = length; }

public double getSide() { return side; }

public void setSide(double side) { this.side = side; }

double getArea() { return area; }
}
public class TestClass {
public static void main(String[] args) throws Exception {
Square sq = new Square(10.0);
sq.area = sq.getSide()*sq.getSide();
System.out.println(sq.getArea());
}
}
You are assigned the task of refactoring the Square class to make it better in terms of encapsulation. What changes will you make to this class?

You had to select 2 option(s)

Q37. What will the following code print when compiled and run?

ArrayList als = new ArrayList(List.of("a", "b", "c"));
Set ss = new HashSet();
ss.addAll(als); //1
als.clear(); //2
System.out.println(ss.size());

You had to select 1 option(s)

Q38. Which of the changes given in options can be done (independent of each other) to let the following code compile and run without errors when its generateReport method is called?

class SomeClass{
String s1 = "green mile"; // 0
public void generateReport( int n ){
String local; // 1
if( n > 0 ) local = "good"; //2
System.out.println( s1+" = " + local ); //3
}
}

You had to select 2 option(s)

Q39. 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")
);

List genreList = new ArrayList();
//INSERT CODE HERE
System.out.println(genreList);

Which of the following options will correctly make genreList refer to a List containing the genres of the books present in books List?

You had to select 4 option(s)

Q40. Assume that a method named 'method1' contains code which may raise a non-runtime (checked) Exception.

What is/are the possible way(s) to declare this method so that it indicates that it expects the caller to handle that exception?

You had to select 2 option(s)

Q41. Given:

public class Student {

public static enum Grade{ A, B , C, D, F}

private String name;
private Grade grade;
public Student(String name, Grade grade){
this.name = name;
this.grade = grade;
}
public String toString(){
return name+":"+grade;
}
//getters and setters not shown
}

What can be inserted in the code below so that it will print:
{C=[S3], A=[S1, S2]}


List ls = Arrays.asList( new Student("S1", Student.Grade.A),
new Student("S2", Student.Grade.A),
new Student("S3", Student.Grade.C));
//INSERT CODE HERE
System.out.println(grouping);

You had to select 1 option(s)

Q42. What will the following class print when compiled and run?

Q43. Which of the following code snippet will print 10 random double values?

You had to select 3 option(s)

Q44. What will the following code print when compiled and run?

public class Paper {
public String title;
public int id;

public Paper(String title, int id){
this.title = title;
this.id = id;
}

public static void main(String[] args) {
var papers = new Paper[]{
new Paper("T1", 1),
new Paper("T2", 2),
new Paper("T3", 3)
};

System.out.println(papers);
System.out.println(papers[1]);
System.out.println(papers[1].id);
}
}

You had to select 1 option(s)

Q45. What will the following code print when compiled and run?

class Base{
void methodA(){
System.out.println("base - MethodA");
}
}

class Sub extends Base{
public void methodA(){
System.out.println("sub - MethodA");
}
public void methodB(){
System.out.println("sub - MethodB");
}
public static void main(String args[]){
Base b=new Sub(); //1
b.methodA(); //2
b.methodB(); //3
}
}

You had to select 1 option(s)

Q46. Given:

String[] p = {"1", "2", "3" };

Which of the following lines of code is/are valid?

You had to select 1 option(s)

Q47. What will the following program print when compiled and run?

class Boo implements Serializable {
transient int ti = 10;
static int si = 20;
}

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

Boo boo = new Boo();
boo.si++;
System.out.println(boo.ti+" "+boo.si);
var fos = new FileOutputStream("c:\\temp\\boo.ser");
var os = new ObjectOutputStream(fos);
os.writeObject(boo);
os.close();

var fis = new FileInputStream("c:\\temp\\boo.ser");
var is = new ObjectInputStream(fis);
boo = (Boo) is.readObject();
is.close();
System.out.println(boo.ti+" "+boo.si);
}
}

You had to select 1 option(s)

Q48. Consider the following code.

LocalDate d = LocalDate.now();
Locale loc = new Locale("fr", "FR");
// 1 insert code here.

What should be inserted at //1 above so that it will print the date in French format?

You had to select 1 option(s)

Q49. What would be the result of compiling and running the following program?

class SomeClass{
public static void main(String args[]){
var size = 10;
var arr = new int[size];
for (var i = 0 ; i < size ; ++i) System.out.println(arr[i]);
}
}

You had to select 1 option(s)

Q50. Consider the following code appearing in the same file:

class Data {
int x = 0, y = 0;
public Data(int x, int y){
this.x = x; this.y = y;
}
}
public class TestClass {
public static void main(String[] args) throws Exception {
Data d = new Data(1, 1);
//add code here
}
}

Which of the following options when applied individually will change the Data object currently referred to by the variable d to contain 2, 2 as values for its data fields?

You had to select 2 option(s)

Q51. Your application consists of two jar files produced by two different teams - accounting-3.2.jar and reporting-5.6.jar. Classes in reporting-5.6.jar uses classes from com.abc.accounts package in accounting-3.2.jar while classes in accounting-3.2.jar do not refer to classes from reporting-5.6.jar.

The application is currently launched using the following command:
java -classpath accounting-3.2.jar;reporting-5.6.jar com.abc.reporting.Main

The accounting team has decided to modularize the new version of their jar but the reporting team hasn't.

Which of the following commands can be used to launch the reporting application using the new version of accounting jar?

You had to select 2 option(s)

Q52. Consider the following code snippet:

//INSERT LINE OF CODE HERE
switch( condition ){
case 1 -> System.out.println("1");
case 2 -> System.out.println("2");
case 3 -> System.out.println("3");
}

What type can be inserted in the code above so that the above code compiles and runs as expected ?

You had to select 2 option(s)

Q53. Which of the following code fragments will NOT cause a compilation error when put inside the following code?

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

//INSERT CODE HERE

}
}

You had to select 2 option(s)

Q54. Consider the following class...

import java.awt.*;
import java.awt.event.*;
class TestFrame extends Frame
{
String s="Message";
public static void main(String args[])
{
var t = new TestFrame();
var b = new Button("press me");
b.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
System.out.println("Message is " +s);
}
}
);
t.add(b);
}
}

What will happen when you attempt to compile and run the program?
NOTE: Although this question uses classes from the AWT package, it is not about those class. You may see exam questions referring to classes that are not on the exam objectives. If you see such classes, you can safely assume that the question is not about them.

You had to select 1 option(s)

Q55. Which statements, when inserted in the code below, will cause an exception at run time?

class B {}
class B1 extends B {}
class B2 extends B {}
public class ExtendsTest{
public static void main(String args[]){
B b = new B();
B1 b1 = new B1();
B2 b2 = new B2();
// insert statement here
}
}

You had to select 1 option(s)