Java Test 4 - 2024

Q1. Identify correct statements about the following code:

interface Readable{ }

sealed class Document implements Readable permits Book{ }

non-sealed class Book implements Readable { }

final class Journal extends Book{ }

You had to select 2 option(s)

Q2. What can be inserted at //2 so that 6 will be printed by the following code?

AtomicInteger ai = new AtomicInteger(5);
//2 INSERT CODE HERE
System.out.println(x);

You had to select 2 option(s)

Q3. Given the following code that appears inside a method:

var values = new ArrayList();
//INSERT CODE HERE

What can be inserted at the given location without causing any compilation error?

You had to select 4 option(s)

Q4. Given:

class Triangle{
public int base;
public int height;
private static double ANGLE;

public static double getAngle();

public static void Main(String[] args) {
System.out.println(getAngle());
}
}

Identify the correct statements:

You had to select 1 option(s)

Q5. What will the following code print when compiled and run?

Instant start = Instant.parse("2022-06-25T16:13:30.00z");
start.plus(10, ChronoUnit.HOURS);
System.out.println(start);

Duration timeToCook = Duration.ofHours(1);
Instant readyTime = start.plus(timeToCook);
System.out.println(readyTime);

LocalDateTime ltd = LocalDateTime.ofInstant(readyTime, ZoneId.of("GMT+2"));
System.out.println(ltd);

You had to select 1 option(s)

Q6. Which of the following code segments will correctly write the text FINAL TEXT at the end of a file file.txt ?

You had to select 1 option(s)

Q7. Which of the following options correctly makes use of java.util.concurrent.Callable?

You had to select 1 option(s)

Q8. Consider the following code snippet:

public class Test{
void test(){
MyClass obj = new MyClass();
obj.name = "jack";
// 1 insert code here
}
}

//In MyClass.java
public class MyClass{
int value;
String name;
}

Which of the following options are required to be inserted at // 1, that will make the object referred to by obj eligible for garbage collection?

You had to select 1 option(s)

Q9. What can be added to the following Person class so that it is properly encapsulated and the code prints 29?

class Person{
//Insert code here
}
public class Employee extends Person{
public static void main(String[] args) {
Employee e = new Employee();
e.setAge(29);
System.out.println(e.getAge());
}
}

You had to select 2 option(s)

Q10. Given:

interface IHello
{
public int hello(int x, int y);
public long hello(long x, long y);
}

Which of the following options are valid definitions in a different file assuming that the above definition is already available?

You had to select 3 option(s)

Q11. 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:\\a\\b\\c");

public static String getValue(){
String x = p1.getName(1).toString();
String y = p1.subpath(1,2).toString();
return x+" : "+y;
}

public static void main(String[] args) {
System.out.println(getValue());
}
}

You had to select 1 option(s)

Q12. Given:

List ls = Arrays.asList(1, 2, 3);
Which of the following options will compute the sum of all Integers in the list correctly?

You had to select 2 option(s)

Q13. What will the following code print when compiled and run?

public class SortTest {
public static void main(String[] args) {
Object[] sa = { 100, 100.0, "100" };
Collections.sort(Arrays.asList(sa), null);
System.out.println(sa[0]+" "+sa[1]+" "+sa[2] );
}

}

You had to select 1 option(s)

Q14. Consider the following code:

public class ArrayTest {

static int[][] table = new int[2][3];

public static void init() {
for (var x = 0; x < table.length; x++) {
for (var y = 0; y < table[x].length; y++) {

//insert code to initialize

}
}
}

public static void multiply() {
for (var x = 0; x < table.length; x++) {
for (var y = 0; y < table[x].length; y++) {

//insert code to multiply

}
}
}
}

Which of the following options can be used in the code above so that the init method initializes each table element to the sum of its row and column number and the multiply method just multiplies the element value by 2?

You had to select 1 option(s)

Q15. Consider the following code:

public static boolean isValid(Path p){

return p.startsWith("temp") && p.endsWith("clients.dat");
}

public static void writeData() {
var p1 = Paths.get("\\temp\\records");
var p2 = p1.resolve("clients.dat");
System.out.println(p2+" "+isValid(p2));

}

What will be printed when the method writeData() is executed?

You had to select 1 option(s)

Q16. Consider the following code snippet:

XXXX m ;
//other code that initializes m
switch( m ){
case 32 -> System.out.println("32");
case 64 -> System.out.println("64");
case 128 -> System.out.println("128");
}

What type can 'm' be of so that the above code compiles and runs as expected ?

You had to select 3 option(s)

Q17. Consider the following lines of code:

boolean greenLight = true;
boolean pedestrian = false;
boolean rightTurn = true;
boolean otherLane = false;

You can go ahead only if the following expression evaluates to 'true' :

(( (rightTurn && !pedestrian || otherLane)
|| ( ? && !pedestrian && greenLight ) ) == true )

What variables can you put in place of '?' so that you can go ahead?

You had to select 1 option(s)

Q18. Identify correct statements about java module descriptor.

You had to select 2 option(s)

Q19. What will the following code print?

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

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

You had to select 1 option(s)

Q20. Given the following code:

and the following commands:

javac TestClass.java
jdeps -summary TestClass.class

What will be the output?

You had to select 1 option(s)

Q21. Given:

public record Journal(int id, String name){
public Journal(){
//1
this.id = 10; this.name="none"; //2
//3
}

public Journal(int id, String name){
this.id = id; this.name=name;
}
}


Identify correct statement(s).

You had to select 1 option(s)

Q22. Consider the following class...

class TestClass{
void probe(Integer x) { System.out.println("In Integer"); } //2

void probe(Object x) { System.out.println("In Object"); } //3

void probe(Long x) { System.out.println("In Long"); } //4

public static void main(String[] args){
String a = "hello";
new TestClass().probe(a);
}
}

What will be printed?

You had to select 1 option(s)

Q23. What will the following code fragment print?

Path p1 = Paths.get("c:\\personal\\.\\photos\\..\\readme.txt");
Path p2 = Paths.get("c:\\personal\\index.html");
Path p3 = p1.relativize(p2);
System.out.println(p3);

You had to select 1 option(s)

Q24. Given the class

// Filename: Test.java
public class Test{
public static void main(String args[]){
for(int i = 0; i< args.length; i++){
System.out.print(" "+args[i]);
}
}
}
Now consider the following 3 options for running the program:
a: java Test
b: java Test param1
c: java Test param1 param2

Which of the following statements are true?

You had to select 2 option(s)

Q25. Consider the following code:

package mypack;
public class TestOuter
{
public static class TestInner
{
public void sayIt(){ System.out.println("hello"); }
}
public static void main(String[] args){
//call here
}
}

Which of the following options are correct?

You had to select 2 option(s)

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

public class TestClass {

public static void main(String[] args){
var k = 2;
do{
System.out.println(k);
}while(--k>0);
}
}

You had to select 1 option(s)

Q27. A developer has written the following code snippet:

Console c = System.console(); //1
String line = c.readLine("Please enter your name:"); //2
System.out.println("Hello, "+line); //3

Which of the following checked exceptions may be thrown by this code?

You had to select 1 option(s)

Q28. What will the following code snippet print?

int count = 0, sum = 0;
do{
if(count % 3 == 0) continue;
sum+=count;
}
while(count++ < 11);
System.out.println(sum);

You had to select 1 option(s)

Q29. Given the following code, which statements can be placed at the indicated position without causing compile and run time errors?

public class Test{
int i1;
static int i2;
public void method1(){
int i;
// ... insert statements here
}
}

You had to select 3 option(s)

Q30. Given that Daylight Savings Time ends on Nov 1 at 2 AM in US/Eastern time zone, what will the following code print -

LocalDateTime ld = LocalDateTime.of(2022, Month.OCTOBER, 31, 10, 0);

ZonedDateTime date = ZonedDateTime.of(ld, ZoneId.of("US/Eastern"));
date = date.plus(Duration.ofDays(1));
System.out.println(date);

date = ZonedDateTime.of(ld, ZoneId.of("US/Eastern"));
date = date.plus(Period.ofDays(1));
System.out.println(date);

You had to select 1 option(s)

Q31. This following code appears in a file named VehicleType.java. Why would it not compile?

//In file VehicleType
package objective1;
public enum VehicleType
{

SUV, SEDAN, VAN, SPORTSCAR;

public VehicleType()
{

}

}

You had to select 1 option(s)

Q32. What will the following class print ?

class InitTest{
public static void main(String[] args){
int a = 10;
int b = 20;
a += (a = 4);
b = b + (b = 5);
System.out.println(a+ ", "+b);
}
}

You had to select 1 option(s)

Q33. Given:

public class Item{
private String name;
private String category;
private double price;

public Item(String name, String category, double price){
this.name = name;
this.category = category;
this.price = price;
}

//accessors not shown
}

What will the following code print?

List items = Arrays.asList(
new Item("Pen", "Stationery", 3.0),
new Item("Pencil", "Stationery", 2.0),
new Item("Eraser", "Stationery", 1.0),
new Item("Milk", "Food", 2.0),
new Item("Eggs", "Food", 3.0)
);

ToDoubleFunction priceF = Item::getPrice; //1

items.stream()
.collect(Collectors.groupingBy(Item::getCategory)) //2
.forEach((a, b)->{
double av = b.stream().collect(Collectors.averagingDouble(priceF)); //3
System.out.println(a+" : "+av);
});

You had to select 1 option(s)

Q34. What will the following program print when run?

class Super{
public String toString(){
return "4";
}
}
public class SubClass extends Super{
public String toString(){
return super.toString()+"3";
}
public static void main(String[] args){
System.out.println( new SubClass() );
}
}

You had to select 1 option(s)

Q35. How many times will the line marked //1 be called in the following code?

var x = 10;
do{
x--;
System.out.println(x); // 1
}while(x<10);

You had to select 1 option(s)

Q36. What will the following code print when run?

public class TestClass {
public static void main(String[] args) throws Exception { //1

var flag = true; //2
switch (flag){ //3
case true -> System.out.println("true");
default -> System.out.println("false");
}

}
}

You had to select 1 option(s)

Q37. Given the following code fragment:

var raf = new RandomAccessFile("c:\\temp\\test.txt", "rwd");

//INSERT CODE HERE

raf.close();

var dis = new DataInputStream(new FileInputStream("c:\\temp\\test.txt"));
String value = dis.readUTF();
System.out.print(value);
dis.close();

Which of the following options can be inserted in the above code so that it will print hello world?

You had to select 1 option(s)

Q38. 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 = new Locale("jp", "JP");
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)

Q39. What changes can be made to the following code so that it will print :

Old Rating A
New Rating R


List ratings = Arrays.asList('U', 'R', 'A');
ratings.stream()
.filter(x->x=='A') //1
.peek(x->System.out.println("Old Rating "+x)) //2
.map(x->x=='A'?'R':x) //3
.peek(x->System.out.println("New Rating "+x)); //4

You had to select 1 option(s)

Q40. How can you initialize a StringBuilder to have a capacity of at least 100 characters?

You had to select 2 option(s)

Q41. Which of the following texts show the right way to specify entries in a resource bundle file?

You had to select 2 option(s)

Q42. Identify correct option(s):

You had to select 2 option(s)

Q43. Which of the following are valid code fragments:

You had to select 2 option(s)

Q44. Assuming that a valid integer will be passed in the command line as first argument, which statements regarding the following code are correct?

public class TestClass{
public static void main(String args[]){
var x = Integer.parseInt(args[0]);
switch(x){
case x < 5 : System.out.println("BIG"); break;
case x > 5 : System.out.println("SMALL");
default : System.out.println("CORRECT"); break;
}
}
}

You had to select 1 option(s)

Q45. Given:

List names = Arrays.asList(1, 2, 3);

How many of the following lines will print exactly 6?

1. System.out.println(names.stream().mapToInt(x->x).sum());

2. System.out.println(names.stream().forEach((sum, x)->sum = sum + x));

3. System.out.println(names.stream().reduce(0, (a, b)->a+b));

4. System.out.println(names.stream().collect(
Collectors.mapping(x->x, Collectors.summarizingInt(x->x))).getSum());

5. System.out.println(names.stream().collect(Collectors.summarizingInt(x->x)).getSum());

You had to select 1 option(s)

Q46. Which of these are NOT legal declarations within a class?

You had to select 1 option(s)

Q47. You are creating an inventory module. This module contains a com.inventory.Queries class that uses a com.acme.DB class. This com.acme.DB class is contained in acme.db module. Which of the following files correctly defines the inventory module?

You had to select 1 option(s)

Q48. What will be the result of trying to compile and execute the following program?

public class TestClass{
public static void main(String args[] ){
var i = 0 ;
int[] iA = {10, 20} ;
iA[i] = i = 30 ;
System.out.println(""+ iA[ 0 ] + " " + iA[ 1 ] + " "+i) ;
}
}

You had to select 1 option(s)

Q49. Which of the following statements will compile without any error?

You had to select 3 option(s)

Q50. Given:

LocalDate d1 = LocalDate.parse("2022-02-05", DateTimeFormatter.ISO_DATE);
LocalDate d2 = LocalDate.of(2022, 2, 5);
LocalDate d3 = LocalDate.now();
System.out.println(d1);
System.out.println(d2);
System.out.println(d3);

Assuming that the current date on the system is 5th Feb, 2022, which of the following will be a part of the output?

You had to select 1 option(s)

Q51. Identify correct statements about the following code:

class Writer{
private static final int LOOPSIZE = 5;
public synchronized void write(Data... da){
for(int i=0; i<LOOPSIZE; i++){
while(!da[0].own(this));
while(!da[1].own(this));
da[0].write(i); da[1].write(i);
da[1].release();
da[0].release();
}
}
}
class Data{
Writer writer; int id;
public Data(int id){ this.id = id; }
public synchronized boolean own(Writer w){
if(writer == null){
writer = w; return true;
}
else return false;
}
public synchronized void release(){ writer = null; }
public void write(int i){
System.out.println("data written W"+i+" D"+id);
}
}
public class TestClass {
public static void main(String[] args) {
var w1 = new Writer();
var w2 = new Writer();
var d1 = new Data(1);
var d2 = new Data(2);
new Thread(()->{w1.write(d1, d2);}).start();
new Thread(()->{w2.write(d1, d2);}).start();
}
}

You had to select 1 option(s)

Q52. What will the following program print?

class Test{
public static void main(String args[]){
int var = 20, i=0;
do{
while(true){
if( i++ > var) break;
}
}while(i<var--);
System.out.println(var);
}
}

You had to select 1 option(s)

Q53. Which of the following interface definitions can be implemented using Lambda expressions?

@FunctionalInterface
interface A{
static void m1(){};
}

interface AA extends A{
void m2();
private void mp(){ }
}

interface AAA extends AA{
void m3();
}

interface B {
default void m1(){ }
}
interface BB extends B {
static void m2(){ };
}
interface C extends BB{
void m3();
}

You had to select 2 option(s)

Q54. Given:

What will be the result?

You had to select 1 option(s)

Q55. Given the following RDBMS table information :

STUDENT Table
SID INT Primary Key
NAME VARCHAR(50)
GPA INT

and the following code:


Statement stmt = connection.createStatement();
ResultSet rs = stmt.executeQuery("select SID, NAME, GPA from STUDENT");
while(rs.next()){
System.out.println( INSERT CODE HERE );
}
connection.close();

What can be inserted in the above code so that it will print the GPA value for each student?

(Assume that items not specified such as import statements and try/catch block are all valid.)

You had to select 2 option(s)