Java Standard Test 14 – 2025

Q1. Given:

//in file Movable.java
package p1;
public interface Movable {
int location = 0;
void move(int by);
public void moveBack(int by);
}


//in file Donkey.java
package p2;
import p1.Movable;
public class Donkey implements Movable{
int location = 200;
public void move(int by) {
location = location+by;
}
public void moveBack(int by) {
location = location-by;
}
}


//in file TestClass.java
package px;
import p1.Movable;
import p2.Donkey;
public class TestClass {
public static void main(String[] args) {
Movable m = new Donkey();
m.move(10);
m.moveBack(20);
System.out.println(m.location);
}
}

Identify the correct statement(s).

Select 1 option(s):

Q2. Identify correct statements about virtual threads.

Select 1 option(s):

Q3. Given:

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

and

Stream sm = Stream.of( new Movie("a1", "a"),
new Movie("a2", "a"),
new Movie("b1", "b"), new Movie("c1", null));

Which of the following code fragments will get the number of movies that do not belong to any genre (i.e. where genre is null)?

Select 1 option(s):

Q4. What is the most likely output of the following code:

var list = List.of("X", "Y");
var result = list.parallelStream().reduce(
list.parallelStream().reduce((a, b)->a+b).get(),
(i, j)->i+j, String::concat
);
System.out.println(result);

Select 1 option(s):

Q5. Given that your module named foo.bar contains the following two source files: src/foo.bar/f/b/Baz1.java and src/foo.bar/f/c/Caz1.java.

Which of the following options can be used to compile this module?

(Assume that all directory paths are relative to the current directory.)

Select 1 option(s):

Q6. What will happen on running the following program?

Select 1 option(s):

Q7. What can be inserted into the following code at //1 so that it will print "Oldboy"?

//imports not shown
class Movie{
static enum Genre {DRAMA, THRILLER, HORROR, ACTION };
private Genre genre;
private String name;
Movie(String name, Genre genre){
this.name = name; this.genre = genre;
}
//accessors not shown
}
public class FilteringStuff {
public static void main(String[] args) {
List movies = Arrays.asList(
new Movie("On the Waterfront", Movie.Genre.DRAMA),
new Movie("Psycho", Movie.Genre.THRILLER),
new Movie("Oldboy", Movie.Genre.THRILLER),
new Movie("Shining", Movie.Genre.HORROR)
);
Predicate horror = mov->mov.getGenre() == Movie.Genre.THRILLER;
Predicate name = mov->mov.getName().startsWith("O");
//1 INSERT CODE HERE
.forEach(mov->System.out.println(mov.getName()));
}

}

Select 1 option(s):

Q8. What will be the result of compiling and running the following code?

class Base{
public short getValue(){ return 1; } //1
}
class Base2 extends Base{
public byte getValue(){ return 2; } //2
}
public class TestClass{
public static void main(String[] args){
Base b = new Base2();
System.out.println(b.getValue()); //3
}
}

Select 1 option(s):

Q9. Given:

public class TestClass
{
public static void main(String[] args) throws IOException {
final Reader reader = new FileReader("aaa.a"); //1
try(reader){
reader.read(); //2
}finally{
reader.read(); //3
}
reader.read(); //4
}
}

Assuming that the fle named aaa.a does not exist, what will be the outcome?

Select 1 option(s):

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

class TestClass{
public static void main(String args[]){
var i = 0;
for (i=1 ; i<5 ; i++) continue; //(1)
for (i=0 ; ; i++) break; //(2)
for ( ; i<5?false:true ; ); //(3)
}
}

Select 1 option(s):

Q11. Given:

record Student(int id, String... subjects){
int rank;
public int getRank(){
return rank;
}
}


public class TestClass{

public static void main(String[] args) {
Student s = new Student(123, new String[]{"math", "science"});
System.out.println(s);
}
}

Which change(s) will enable the code to compile?

Select 1 option(s):

Q12. Given:

DoubleStream ds = DoubleStream.of(1.0, 2.0, 3.0);
//INSERT CODE HERE
ds.map(doubleF.apply(5.0)).forEach(System.out::println);

Which of the following statements can be inserted in the above code?

Select 1 option(s):

Q13. What will be the output of the following code snippet?

int a = 1;
int[] ia = new int[10];
int b = ia[a];
int c = b + a;
System.out.println(b = c);

Select 1 option(s):

Q14. A java source file contains the following code:

interface I {
int getI(int a, int b);
}

interface J{
int getJ(int a, int b, int c);
}

abstract class MyIJ implements J , I { }

class MyI{
int getI(int x, int y){ return x+y; }
}

interface K extends J{
int getJ(int a, int b, int c, int d);
}

Identify the correct statements:

Select 1 option(s):

Q15. What would be the result of attempting to compile and run the following program?

class TestClass{
static TestClass ref;
String[] arguments;
public static void main(String args[]){
ref = new TestClass();
ref.func(args);
}
public void func(String[] args){
ref.arguments = args;
}
}

Select 1 option(s):

Q16. What will the following program print?

class Test{
public static void main(String args[]){
int i=0, j=0;
X1: for(i = 0; i < 3; i++){
X2: for(j = 3; j > 0; j--){
if(i < j) continue X1;
else break X2;
}
}
System.out.println(i+" "+j);
}
}

Select 1 option(s):

Q17. What will the following code print when run?

public class TestClass {
public static void main(String[] args) throws Exception {
var sa = new String[]{"a", "b", "c"};
for(String s : sa){
if("b".equals(s)) continue;
System.out.println(s);
if("b".equals(s)) break;
System.out.println(s+" again");
}
}
}

Select 1 option(s):

Q18. What will be the output of the following program?

class Test
{
static int i1, i2, i3;
public static void main(String[] args)
{
try
{
test(i1 = 1, oops(i2=2), i3 = 3);
} catch (Exception e)
{
System.out.println(i1+" "+i2+" "+i3);
}
}
static int oops(int i) throws Exception
{
throw new Exception("oops");
}
static int test(int a, int b, int c) {
return a + b + c;
}
}

Select 1 option(s):

Q19. Given the following declarations, identify which statements will return true:

Integer i1 = 1;
Integer i2 = new Integer(1);
int i3 = 1;
Byte b1 = 1;
Long g1 = 1L;
Double d = 1.0;

Select 2 option(s):

Q20. You have a file named customers.dat in c:\company\records directory. You want to copy all the lines in this file to another file named clients.dat in the same directory and you have the following code to do it:

public static void writeData() {
Path p1 = Paths.get("c:\\company\\records\\customers.dat");

//LINE 20 - INSERT CODE HERE

try (
var br = new BufferedReader(new FileReader(p1.toFile()));
var bw = new BufferedWriter(new FileWriter(p2.toFile()))) {
String line = null;
while ((line = br.readLine()) != null) {

bw.write(line);
bw.newLine();
}
}catch(Exception e){
e.printStackTrace();
}
}

Which of the following options can be inserted independent of each other at //LINE 20 to make it work?

Assume that the current directory for the program when it runs is c:\code.

Select 2 option(s):

Q21. What will the following code print when run?

public class TestClass {
public static void m1() throws Exception{
throw new Exception("Exception from m1");
}
public static void m2() throws Exception{
try{
m1();
}catch(Exception e){
//Can't do much about this exception so rethrow it
throw e;
}finally{
throw new RuntimeException("Exception from finally");
}

}

public static void main(String[] args) {
try{
m2();
}catch(Exception e){
Throwable[] ta = e.getSuppressed();
for(Throwable t : ta) {
System.out.println(t.getMessage());
}
}
}
}

Select 1 option(s):

Q22. Consider following classes:

//In File Other.java
package other;
public class Other { public static String hello = "Hello"; }

//In File Test.java
package testPackage;
import other.*;
class Test{
public static void main(String[] args){
String hello = "Hello", lo = "lo";
System.out.print((testPackage.Other.hello == hello) + " "); //line 1
System.out.print((other.Other.hello == hello) + " "); //line 2
System.out.print((hello == ("Hel"+"lo")) + " "); //line 3
System.out.print((hello == ("Hel"+lo)) + " "); //line 4
System.out.println(hello == ("Hel"+lo).intern()); //line 5
}
}
class Other { static String hello = "Hello"; }
What will be the output of running class Test?

Select 1 option(s):

Q23. Given:

Instant now = Instant.now();
Instant now2 = //INSERT CODE HERE
System.out.println(now2);

Which of the following options can be inserted in the above code without causing any compilation or runtime errors?

Select 1 option(s):

Q24. Consider the code shown below:

public class TestClass{
public static int switchTest(int k){
var j = 1;
switch(k){
case 1: j++;
case 2: j++;
case 3: j++;
case 4: j++;
case 5: j++;
default : j++;
}
return j + k;
}
public static void main(String[] args){
System.out.println( switchTest(4) );
}
}

What will it print when compiled and run?

Select 1 option(s):

Q25. What will the following class print ?

class Test{
public static void main(String[] args){
int[][] a = { { 00, 01 }, { 10, 11 } };
int i = 99;
try {
a[val()][i = 1]++;
} catch (Exception e) {
System.out.println( i+", "+a[1][1]);
}
}
static int val() throws Exception {
throw new Exception("unimplemented");
}
}

Select 1 option(s):

Q26. Given:

class Course{
private String id;
private String name;

public Course(String id, String name){
this.id = id; this.name = name;
}
//accessors not shows
}

What will the following code print?

List cList = Arrays.asList(
new Course("803", "OCAJP 7"),
new Course("808", "OCAJP 8"),
new Course("809", "OCPJP 8")
);

cList.stream().filter(c->c.getName().indexOf("8")>-1)
.map(c->c.getId())
.collect(Collectors.joining("1Z0-"));
cList.stream().forEach(c->System.out.println(c.getId()));

Select 1 option(s):

Q27. Given:

class StaticTest{

void m1(){
StaticTest.m2(); // 1
m4(); // 2
StaticTest.m3(); // 3
}

static void m2(){ } // 4

void m3(){
m1(); // 5
m2(); // 6
StaticTest.m1(); // 7
}

static void m4(){ }
}

Which of the lines will fail to compile?

Select 2 option(s):

Q28. Identify correct statements about the following code:

List list1 = List.of("A", "B");
List list2 = List.copyOf(list1);
list1.add("C"); //1
list2.add("D"); //2
System.out.println(list1+" "+list2);

Select 1 option(s):

Q29. Given:

public class TestClass {
static int val = 10;
public static int reduce(int val){
class Inner{
public int reduce(int mval){
return mval-val--;
}
}
val--;
return new Inner().reduce(val);
}

public static void main(String[] args) {
reduce(5);
System.out.println(val);
}
}

Select 1 option(s):

Q30. Given:

List strList = Arrays.asList("a", "aa", "aaa");
Function f = x->x.length();
Consumer c = x->System.out.print("Len:"+x+" ");
Predicate p = x->"".equals(x);
strList.forEach( *INSERT CODE HERE* );

What can be inserted in the code above?

Select 1 option(s):

Q31. Consider the following code:

import java.io.*;
public class Test
{
public static void main(String[] args) throws Exception
{
var fw = new FileWriter("text.txt");
// fw.write("hello"); //1
fw.close();
}
}

Which of the following statements are correct?

Select 1 option(s):

Q32. Which of these expressions will return true?

Select 4 option(s):

Q33. Identify correct statements about the following code:

Select 1 option(s):

Q34. Given:

interface Carnivore{
default int calories(List food){
return food.size()*100;
}
int eat(List foods);
}
class Tiger implements Carnivore{
public int eat(List foods){
System.out.println("Eating "+foods);
return foods.size()*200;
}
}
public class TestClass {
public static int size(List names){
return names.size()*2;
}
public static void process(List names, Carnivore c){
c.eat(names);
}

public static void main(String[] args) {
List fnames = Arrays.asList("a", "b", "c");
Tiger t = new Tiger();

INSERT CODE HERE

}
}

Which of the following options can be inserted independent of each other in the code above without any compilation error?

Select 3 option(s):

Q35. Given:

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

What is the result?

Select 1 option(s):

Q36. Consider that you are writing a set of classes related to a new Data Transmission Protocol and have created your own exception hierarchy derived from java.lang.Exception as follows:

nthu.trans.ChannelException
+-- enthu.trans.DataFloodingException
+-- enthu.trans.FrameCollisionException
(Both enthu.trans.DataFloodingException and enthu.trans.FrameCollisionException extend ChannelException)

You have a TransSocket class that has the following method:
long connect(String ipAddr) throws ChannelException

Now, you also want to write another "AdvancedTransSocket" class, derived from "TransSocket" which overrides the above mentioned method. Which of the following are valid declaration of the overriding method?

Select 2 option(s):

Q37. 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 statements are true about this code if it is run in the background by a scheduler?

Select 1 option(s):

Q38. Given that the file test.txt is accessible and contains multiple lines, which of the following code fragments will correctly print all the lines from the file?

Select 2 option(s):

Q39. Which of the following is/are valid instantiations and initializations of a multi dimensional array?

Select 2 option(s):

Q40. Consider the following code:

import java.util.*;
import java.text.*;

public class TestClass
{
public static void main(String[] args) throws Exception
{
double amount = 53000.35;

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

//1 create formatter here.

System.out.println( formatter.format(amount) );
}
}

How will you create formatter using a factory at //1 so that the output is in Japanese Currency format?

Select 2 option(s):

Q41. Given:

public class TestClass
{
public static void main(String args[])
{
A ab = new B();
A ac = new C();

if( ac instanceof B b1){
b1.b();
if(b1 instanceof C c1){
c1.c();
}
}else{
ac.a();
}
}
}

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

What will be the output?

Select 1 option(s):

Q42. Which of the following are true regarding overloading of a method?

Select 1 option(s):

Q43. What will the following code print?

IntStream is = IntStream.range(1, 6);
IntStream is2 = is.takeWhile(x-> x%2==0);
is2.forEach(System.out::print);

Select 1 option(s):

Q44. Given:

String INPUT_FILE = "c:\\temp\\src\\foo.bar\\module-info.java";

Assuming the file exists, which of the following options will print the contents of the file?

Select 2 option(s):

Q45. What will the following method print?

public static void iCanDoThis(){
int x = 2;
int y = ~x; //LINE 2
int z = x ^ y; //LINE 3

boolean flag = x z++; //LINE 4

if(flag) {
flag = x > y && x > --z; //LINE 6
}

if(z>-1){ //LINE 8
--z;
} else z++;

System.out.println(flag+" "+z); //LINE 11
}

Select 1 option(s):

Q46. Given the following code:

enum Title
{
MR("Mr. "), MRS("Mrs. "), MS("Ms. ");
private String title;
private Title(String s){
title = s;
}
public String format(String first, String last){
return title+" "+first+" "+last;
}
}

//INSERT CODE HERE


Identify valid code snippets ..

(Assume that Title is accessible wherever required.)

Select 4 option(s):

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

Collection col = new HashSet();
col.add(1);
var list1 = List.of(col); //1
col.add(2); //2
var list2 = List.copyOf(col); //3
System.out.println(list1+", "+list2);

Select 1 option(s):

Q48. Which of the following are valid at line 1?

public class X{
//line 1: insert code here.
}

Select 2 option(s):

Q49. Given:

module foo.filter{
requires api;
provides api.Filter with foo.DoNothingFilter;
}

Assuming that api.Filter is an interface with just a single method List filter(List l), which of the following is a valid implementation of foo.DoNothingFilter class?

Select 1 option(s):

Q50. What will the following code print?

enum AccountType{
CHECKING("Checking account"), SAVINGS("Savings account"),
FD("Fixed Deposit");

private String desc;
AccountType(String desc){
this.desc = desc;
}

@Override
public String toString(){
return "Acct type:"+super.toString();
}

}

public class TestClass {
public static void main(String[] args) {
var at = AccountType.valueOf("FD");
System.out.println(at.ordinal()+" "+at);
}
}

Select 1 option(s):