Free OCP: Java SE 11 Certification (1Z0-819) Practice Test 6

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Welcome to your Java Test - 6

Name

Phone

Question: What will the following code print?

Map map1 = new HashMap();
map1.put("a", 1);
map1.put("b", 1);
map1.merge("b", 1, (i1, i2)->i1+i2);
map1.merge("c", 3, (i1, i2)->i1+i2);
System.out.println(map1);

Select 1 option(s)

{a=1, b=2, c=3}

{a=1, b=1, c=3}

{a=1, b=2}

A NullPointerException will be thrown at run time.

None

Question: Which of the given option when inserted in the code below will make the code print true?

List values = Arrays.asList("Alpha A", "Alpha B", "Alpha C");
//INSERT CODE HERE
System.out.println(flag);

Select 1 option(s)

boolean flag = values.stream().allMatch(str->str.equals("Alpha"));

boolean flag = values.stream().findFirst().get().equals("Alpha");

boolean flag = values.stream().findAny().get().equals("Alpha");

boolean flag = values.stream().anyMatch(str->str.equals("Alpha"));

None of the above.

None

Question: When is the Object created at line //1 eligible for garbage collection?

public class TestClass{
public Object getObject(){
Object obj = new String("aaaaa"); //1
Object objArr[] = new Object[1]; //2
objArr[0] = obj; //3
obj = null; //4
objArr[0] = null;//5
return obj; //6
}
}

Select 1 option(s)

Just after line 2.

Just after line 3.

Just after line 4.

Just after line 5.

Just after line 6.

None

Question: Given the following code:

interface Device {
public abstract void switchOn();
}

abstract class Router /* LOCATION 1 */ {
/* LOCATION 2 */
public void switchOn(){ }

public abstract void reset();
}

class MimoRouter extends Router implements Device{
/* LOCATION 3 */
}

Which code, when inserted at one or more marked locations, would allow classes Router and MimoRouter to compile?

(Consider each option as independent of other options.)

Select 2 option(s)

implements Device //at location 1
@Override //at location 2

public void reset(){ } //at location 3

@Override //at location 2
public void reset() { } //at location 3

@Override //at location 3
void switchOn(){ } //at location 3
@Override //at location 3
public void reset(){ }//at location 3

@Override //at location 2 and 3
public void switchOn(){ } //at location 2 and 3
public void reset(){ }//at location 3

implements Device //at location 1
@Override //at location 2
public void reset(){ }//at location 3

Question: Consider the following code:

class MyClass { }
public class TestClass{
MyClass getMyClassObject(){
MyClass mc = new MyClass(); //1
return mc; //2
}
public static void main(String[] args){
TestClass tc = new TestClass(); //3
MyClass x = tc.getMyClassObject(); //4
System.out.println("got myclass object"); //5
x = new MyClass(); //6
System.out.println("done"); //7
}
}

After what line the MyClass object created at line 1 will be eligible for garbage collection?

Select 1 option(s)

Never till the program ends.

None

Question: Consider the following class hierarchy

class A{
public void m1() { }
}
class B extends A{
public void m1() { }
}
class C extends B{
public void m1(){
/* //1
... lot of code.
*/
}
}

Select 2 option(s)

You cannot access class A's m1() from class C for the same object ( i.e. this).

You can access class B's m1() using super.m1() from class C.

You can access class A's m1() using ( (A) this ).m1() from class C.

You can access class A's m1() using super.super.m1() from class C.

Question: 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?

Select 2 option(s)

values.sort( var a, var b-> a.compareTo(b) );

values.sort( (a, b) -> a.compareTo(b) );
values.forEach( System.out::println );

values.sort();
values.forEach( System.out::println);

values.removeIf((var k)->k.equals("a") );

String[] sa = values.toArray();

Question: Your application is packaged in myapp.jar and depends on a jar named datalayer.jar, which in turn depends on mysql-connector-java-8.0.11.jar. The following packages exist in these jars:

myapp.jar: com.abc.myapp
datalayer.jar: com.abc.datalayer
mysql-connector-java-8.0.11.jar: com.mysql.jdbc

You have decided to modularize your application even though datalayer and mysql libraries are still not modularlized. Which of the following would be a valid module-info for your app?

Select 1 option(s)

module abc.myapp{
requires com.abc.datalayer;
}

module abc.myapp{
exports com.abc.myapp;
}

module abc.myapp{
requires datalayer;
}

module abc.myapp{
requires datalayer;
requires mysql-connector-java;
}

module abc.myapp{
requires datalayer;
requires mysql-connector-java-0.0.11;
}

module abc.myapp{
requires com.abc.datalayer;
requires com.mysql.jdbc;
}

None

Question: Given:

enum Card
{
HEART, CLUB, SPADE, DIAMOND;

public boolean isRed(){
return switch(this){
case HEART, DIAMOND -> true;
default -> false;
};
}
}

What will the following code print?

Arrays.stream(Card.values()).dropWhile(c->c.isRed());
switch(Card.valueOf("HEART")){
case HEART -> System.out.println("heart");
case CLUB -> System.out.println("club");
case SPADE -> System.out.println("spade");
case DIAMOND -> System.out.println("diamond");
default -> System.out.println("unknown");
}

Select 1 option(s)

heart

unknown

It will not compile.

It will throw a NullPointerException at run time.

None

10.

Question: Consider the following classes...

class Point { int x, y; }
class ColoredPoint extends Point { int color; }
class Test
{
static void test(ColoredPoint p, Point q)
{
System.out.println("(ColoredPoint, Point)");
}
static void test(Point p, ColoredPoint q)
{
System.out.println("(Point, ColoredPoint)");
}
public static void main(String[] args)
{
ColoredPoint cp = new ColoredPoint();
test(cp, cp);
}
}

The above code will print (ColoredPoint, Point) when compiled and run.

Select 1 option(s)

True

False

None

11.

Question: Consider the following class...

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

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

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

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

public static void main(String[] args){
double a = 10;
new TestClass().probe(a);
}
}

What will be printed?

Select 1 option(s)

In Number

In Object

In Long

In Integer

It will not compile.

None

12.

Question: Which of the following code fragments will successfully initialize a two-dimensional array of chars named cA with a size such that cA[2][3] refers to a valid element?

1.
char[][] cA = { { 'a', 'b', 'c' }, { 'a', 'b', 'c' } };
2.
char cA[][] = new char[3][];
for (int i=0; i<cA.length; i++) cA[i] = new char[4];
3.
char cA[][] = { new char[ ]{ 'a', 'b', 'c' } , new char[ ]{ 'a', 'b', 'c' } };
4
char cA[3][2] = new char[][] { { 'a', 'b', 'c' }, { 'a', 'b', 'c' } };
5.
char[][] cA = { "1234", "1234", "1234" };

6.
var cA[][] = new char[3][];
for (var i=0; i<cA.length; i++) cA[i] = new char[4];

Select 1 option(s)

1, 3

4, 5

2, 3

1, 2, 3

2, 6

1, 3, 6

2, 3, 6

None

13.

Question: Identify correct constructs.

Select 1 option(s)

try {
for( ;; );
}finally { }

try {
File f = new File("c:\\a.txt");
} catch { f = null; }

int k = 0;
try {
k = callValidMethod();
}
System.out.println(k);
catch { k = -1; }

try {
try {
Socket s = new ServerSocket(3030);
}catch(Exception e) {
s = new ServerSocket(4040);
}
}

try {
s = new ServerSocket(3030);
}
catch(Exception t){ t.printStackTrace(); }
catch(IOException e) {
s = new ServerSocket(4040);
}
catch(Throwable t){ t.printStackTrace(); }

int x = validMethod();
try {
if(x == 5) throw new IOException();
else if(x == 6) throw new Exception();
}finally {
x = 8;
}
catch(Exception e){ x = 9; }

None

14.

Question: Given:

class Base{
public List transform(Set list){
//valid code
};
}

class Derived extends Base{
*INSERT CODE HERE*
//valid code
}
}

What can be inserted in the above code?

Select 2 option(s)

public List< String > transform(Set< String > list){

public List< Object > transform(Set< CharSequence > list){

public ArrayList< CharSequence > transform(Set< CharSequence > list){

public List< StringBuilder > transform(Set< CharSequence > id){

public List< Integer > transform(TreeSet< CharSequence > id){

public ArrayList< String > transform(Set< String > id){

15.

Question: Given:

interface Runner {
public void run();
}

Which of the following is/are valid lambda expression(s) that capture(s) the above interface?

Select 2 option(s)

-> System.out.println("running...");

void -> System.out.println("running...")

() -> System.out.println("running...")

() -> { System.out.println("running..."); return; }

(void) -> System.out.println("running...")

-> System.out.println("running...")

16.

Question: Assuming that the local time when the following code is executed is 9.30 AM, what will it print?

LocalTime now = LocalTime.now();
LocalTime gameStart = LocalTime.of(10, 15);
long timeConsumed = 0;
long timeToStart = 0;
if(now.isAfter(gameStart)){
timeConsumed = gameStart.until(now, ChronoUnit.HOURS);
}else{
timeToStart = now.until(gameStart, ChronoUnit.HOURS);
}
System.out.println(timeToStart + " " + timeConsumed);

Select 1 option(s)

0 45

0 0

45 0

None of the above.

None

17.

Question: What will the following code print when compiled and run?

import java.io.Serializable;
class Booby{
int i; public Booby(){ i = 10; System.out.print("Booby"); }
}
class Dooby extends Booby implements Serializable {
int j; public Dooby(){ j = 20; System.out.print("Dooby"); }
}
class Tooby extends Dooby{
int k; public Tooby(){ k = 30; System.out.print("Tooby"); }
}
public class TestClass {
public static void main(String[] args) throws Exception{

var t = new Tooby();
t.i = 100;
var oos = new ObjectOutputStream(new FileOutputStream("c:\\temp\\test.ser"));
oos.writeObject(t); oos.close();

var ois = new ObjectInputStream(new FileInputStream("c:\\temp\\test.ser"));
t = (Tooby) ois.readObject();ois.close();

System.out.println(t.i+" "+t.j+" "+t.k);
}
}

Select 1 option(s)

Booby Dooby Tooby 100 20 30

Booby Dooby Tooby Booby Dooby Tooby 10 20 30

Booby Dooby Tooby Booby 10 20 30

Booby Dooby Tooby Booby 0 20 30

Booby Dooby Tooby Booby 100 20 30

Booby Dooby Tooby Booby Dooby Tooby 100 20 30

None

18.

Question: What will the following method return if called with an argument of 7?

public int transformNumber(int n){
var radix = 2;
var output = 0;
output += radix*n;
radix = output/radix;
if(output<14){
return output;
}
else{
output = output*radix/2;
return output;
}
else {
return output/2;
}
}

Select 1 option(s)

Compilation fails.

None

19.

Question: Consider the following code:

import java.util.*;
public class TestClass
{
static String[] sa = { "charlie", "bob", "andy", "dave" };
public static void main(String[] args)
{
// 1 insert code here.
}
}

Which of the given options (independent of each other or together) must be inserted at //1 so that it will print 2?

Select 2 option(s)

System.out.println(Arrays.search(sa, "andy"));

System.out.println(Arrays.linearSearch(sa, "andy"));

Arrays.sort(sa);

System.out.println(Arrays.binarySearch(sa, "charlie"));

Only option 2 is enough.

20.

Question: Given:

class Booby{
}
class Dooby extends Booby{
}
class Tooby extends Dooby{
}

and the following declarations:

var bL = new ArrayList();
var tL = new ArrayList();

List bV = //code for initialization
List dV = //code for initialization

Which of the following statements are valid?

Select 4 option(s)

dV.add(new Dooby(){ });

bV = bL;

dV = bL;

bV = tL;

dV = tL;

bV.add(new Dooby(){ });

21.

Question: What will the following code snippet print?

Object t = new Integer(107);
int k = (Integer) t.intValue()/9;
System.out.println(k);

Select 1 option(s)

It will not compile.

It will throw an exception at runtime.

None

22.

Question: In which sequence will the characters a, b, and, c be printed by the following program?

import java.util.* ;
public class ListTest{
public static void main(String args[]){
List s1 = new ArrayList( );
s1.add("a");
s1.add("b");
s1.add(1, "c");
List s2 = new ArrayList( s1.subList(1, 1) );
s1.addAll(s2);
System.out.println(s1);
}
}

Select 1 option(s)

The sequence a, b, c is printed.

The sequence a, b, c, b is printed.

The sequence a, c, b, c is printed.

The sequence a, c, b is printed.

None of the above.

None

23.

Question: Given:

1. Java source file location: src/moduleA/a/A.java
2. Expected class file location: out/moduleA/a/A.class

Which of the following commands will generate A.class in the expected directory?

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

Select 1 option(s)

javac --module-path src --output-path out src/moduleA/a/A.java

javac --module-source-path src --output-path out src/moduleA/a/A.java

javac --module-source-path src -d out src/moduleA/a/A.java

javac --module-source-path src --module-path out src/moduleA/a/A.java

None

24.

Question: Add description here!Consider the following interface definition:

interface Bozo{
int type = 0;
public void jump();
}

Now consider the following class:

public class Type1Bozo implements Bozo{
public Type1Bozo(){
type = 1;
}

public void jump(){
System.out.println("jumping..."+type);
}

public static void main(String[] args){
Bozo b = new Type1Bozo();
b.jump();
}
}

What will the program print when compiled and run?

Select 1 option(s)

jumping...0

jumping...1

This program will not compile.

It will throw an exception at runtime.

None

25.

Question: How will you initialize a SimpleDateFormat object so that the following code will print the full text time zone of the given date?

System.out.println(sdf.format(new Date()));

Note: Although this SimpleDateFormat is not mentioned explicitly in the exam objectives, it is used a lot in legacy code. Read about this class if you have time. Otherwise, leave it.

Select 1 option(s)

SimpleDateFormat sdf = new SimpleDateFormat("tttt", Locale.FRANCE);

SimpleDateFormat sdf = new SimpleDateFormat("T", Locale.FRANCE);

SimpleDateFormat sdf = new SimpleDateFormat("z", Locale.FRANCE);

SimpleDateFormat sdf = new SimpleDateFormat("zzzz", Locale.FRANCE);

SimpleDateFormat sdf = new SimpleDateFormat("XXX", Locale.FRANCE);

None

26.

Question: What will the following program print?

public class TestClass{
public static void main(String[] args){
int x = 1;
int y = 0;
if( x/y ) System.out.println("Good");
else System.out.println("Bad");
}
}

Select 1 option(s)

Good

Bad

Exception at runtime saying division by Zero.

It will not compile.

None of the above.

None

27.

Question: What will be the output of the following class:

public class TestClass{
public void testRefs(String str, StringBuilder sb){
str = str + sb.toString();
sb.append(str);
str = null;
sb = null;
}
public static void main(String[] args){
String s = "aaa";
StringBuilder sb = new StringBuilder("bbb");
new TestClass().testRefs(s, sb);
System.out.println("s="+s+" sb="+sb);
}
}

Select 1 option(s)

s=aaa sb=bbb

s=null sb=null

s=aaa sb=null

s=null sb=bbbaaa

s=aaa sb=bbbaaabbb

None

28.

Question: What will the code shown below print when run?

class Wrapper{
int w = 10;
}

public class TestClass{

static Wrapper changeWrapper(Wrapper w){
w = new Wrapper();
w.w += 9;
return w;
}

public static void main(String[] args){
var w = new Wrapper();
w.w = 20;
changeWrapper(w);
w.w += 30;
System.out.println(w.w);
w = changeWrapper(w);
System.out.println(w.w);
}
}

Select 2 option(s)

29.

Question: Consider the following class...

class TestClass{
int x;
public static void main(String[] args){
// lot of code.
}
}

Select 1 option(s)

By declaring x as static, main can access this.x

By declaring x as public, main can access this.x

By declaring x as protected, main can access this.x

main cannot access this.x as it is declared now.

By declaring x as private, main can access this.x

None

30.

Question: What will the following code snippet print:

Float f = null;
try{
f = Float.valueOf("12.3");
String s = f.toString();
int i = Integer.parseInt(s);
System.out.println(""+i);
}
catch(Exception e){
System.out.println("trouble : "+f);
}

Select 1 option(s)

trouble : null

trouble : 12.3

trouble : 0.0

None

31.

Question: Consider the following code:

class A{
A() { print(); }
void print() { System.out.print("A "); }
}
class B extends A{
int i = 4;
public static void main(String[] args){
A a = new B();
a.print();
}
void print() { System.out.print(i+" "); }
}

What will be the output when class B is run ?

Select 1 option(s)

It will print A 4

It will print A A

It will print 0 4

It will print 4 4

None of the above.

None

32.

Question: What will be the result of attempting to compile the following program?

public class TestClass{
long l1;
public void TestClass(long pLong) { l1 = pLong ; } //(1)
public static void main(String args[]){
TestClass a, b ;
a = new TestClass(); //(2)
b = new TestClass(5); //(3)
}
}

Select 1 option(s)

A compilation error will be encountered at (1), since constructors should not specify a return value.

A compilation error will be encountered at (2), since the class does not have a default constructor.

A compilation error will be encountered at (3).

The program will compile correctly.

It will not compile because parameter type of the constructor is different than the type of value passed to it.

None

33.

Question: Given:

public class Square {
private double side = 0; // LINE 2

public static void main(String[] args) { // LINE 4
Square sq = new Square(); // LINE 5
side = 10; // LINE 6
}
}

What can be done to make this code compile and run?

Select 1 option(s)

replace // LINE 2 with:
private int side = 0;

replace // LINE 2 with:
public int side = 0;

replace // LINE 5 with:
double sq = new Square();

replace // LINE 6 with:
sq.side = 10;

None

34.

Question: Given:

class Person{
String name;
String dob;
public Person(String name, String dob){
this.name = name; this.dob = dob;
}
}
class MySorter {
public int compare(Person p1, Person p2){
return p1.dob.compareTo(p2.dob);
}
}
public class SortTest {
public static int diff(Person p1, Person p2){
return p1.dob.compareTo(p2.dob);
}

public static int diff(Date d1, Date d2){
return d1.compareTo(d2);
}
public static void main(String[] args) {
ArrayList al = new ArrayList();
al.add(new Person("Paul", "01012000"));
al.add(new Person("Peter", "01011990"));
al.add(new Person("Patrick", "01012002"));

INSERT CODE HERE
}
}

and the following lines of code:
I java.util.Collections.sort(al, (p1, p2)->p1.dob.compareTo(p2.dob));

II java.util.Collections.sort(al, SortTest::diff);

III java.util.Collections.sort(al, new MySorter()::compare);

IV java.util.Arrays.sort(al, SortTest::diff);

How many of the above lines can be inserted into the given code, independent of each other, to sort the list referred to by al?

Select 1 option(s)

None of these

None

35.

Question: Which of the given options if put at //1 will compile without any error?

public class TestClass
{
public class A
{
}
public static class B
{
}
public void useClasses()
{
//1
}
}

Select 1 option(s)

new TestClass().new A();

new TestClass.B();

new A();

new TestClass.A();

All of these are valid.

None

36.

Question: You are creating an enthu.questionbank module that depends on enthu.internal.db and enthu.external.feeds modules. Which of the following files correctly defines this module?

Select 1 option(s)

//In file module-info.java:
module enthu.questionbank{
requires enthu.internal.db, enthu.external.feeds;
}

//In file module-info.java:
module enthu.questionbank{
uses enthu.internal.db, enthu.external.feeds;
}

//In file module-info.java:
module enthu.questionbank{
import enthu.internal.db;
import enthu.external.feeds;
}

//In file module-info.java:
module enthu.questionbank{
require enthu.internal.db;
require enthu.external.feeds;
}

None of the above are valid.

None

37.

Question: How can you declare 'i' so that it is not visible outside the package test.

package test;
public class Test{
XXX int i;
/* irrelevant code */
}

Select 2 option(s)

private

public

protected

No access modifier

friend

38.

Question: Given a Course class with appropriate constructor and methods and the following code:

List s1 = //create a list with a few Course objects
String testCategory = "Java";
Integer comparisonCode = 0;
long l = s1.stream()
.peek(new Consumer(){
public void accept(Course c){
c.printPassPercent();
}})
.map(c -> testCategory.compareToIgnoreCase(c.getCategory()))
.filter(a->a == 0)
.count();
System.out.println(l);

Which of the method arguments can be changed to use method references?

Select 2 option(s)

Course::printPassPercent

testCategory::compareToIgnoreCase

comparisonCode::equals

comparisonCode::equals(0)

Integer::equals(comparisonCode)

Course::getId == comparisonCode

39.

Question: Given:

var data = new ArrayList();
data.add("A");
data.add(100); //1
data.add("C");
data.set(0, 200); //2
data.remove(2); //3
data.set(2, 101L);//4
System.out.println(data);

What will be the output?

Select 1 option(s)

It will not compile.

Exception at run time on line marked //1.

Exception at run time on line marked //2.

Exception at run time on line marked //3.

Exception at run time on line marked //4.

[200, 100, 101]

None

40.

Question: Which of the following expressions can be used to implement a Function ?

Select 3 option(s)

(a)-> Integer.toHexString(a)

a -> Integer::toHexString

Integer::toHexString

i::toHexString

toHexString

val -> val + 1

(Integer a)-> Integer.toHexString(a)

Integer a-> Integer.toHexString(a)

41.

Question: Assuming that a file named "a.java" exists in c:\pathtest\ as well as in c:\pathtest\dir2, what will happen when the following code is compiled and run?

//imports not shown
public class MoveTest {

public static void main(String[] args) throws IOException {
Path p1 = Paths.get("c:\\pathtest\\a.java");
Path p2 = Paths.get("c:\\pathtest\\dir2\\a.java");
Files.move(p1, p2, StandardCopyOption.ATOMIC_MOVE);
Files.delete(p1);
System.out.println(p1.toFile().exists()+" "+
p2.toFile().exists());
}
}

Select 1 option(s)

It will not compile.

It will terminate cleanly after printing false true.

It will terminate cleanly after printing true true.

It will terminate cleanly after printing true false.

It will terminate cleanly after printing false false.

It will throw an exception at run time.

The outcome is JVM/platform dependent.

None

42.

Question: Given:

record Student(int id, String name) {
}

Which of the following methods will be added automatically to this record?

Select 3 option(s)

public String getName(){ return name; }

public setName(String name){ this.name = name; }

public final boolean equals(Object)

public final int hashCode()

public final String toString()

43.

Question: Given:

public class Device implements AutoCloseable{
boolean open = false;
public Device(){
open = true;
}

public String read() throws IOException{
throw new IOException("Can't read!");
}

public boolean isOpened(){
return open;
}

public void close(){
open = false;
System.out.println("Device closed");
}

public static void main(String[] args) {
Device d1 = new Device();
try(d1;
Device d2 = new Device();
Device d3 = new Device()){
d2.read();
}catch(Exception e){
System.out.println("Got Exception "+e.getMessage());
}
}
}

What is the status of Device objects at the end of the try/catch blocks?

Select 1 option(s)

All three will be closed.

d1 and d3 will be closed but d2 will remain open.

d1 and d2 will be closed but d3 will remain open.

d2 will be closed but d1 and d3 will remain open.

All three will remain opened.

Compilation failure.

None

44.

Question: What will be the output when the following program is run?

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

Select 1 option(s)

0 0 will be printed twice.

0 0 will be printed once.

It will keep on printing 0 0

It will not compile.

It will print 0 0 and then 0 1.

None

45.

Question: An existing application contains the following code:

interface AmountValidator{
public boolean checkAmount(double value);
}
public class Account {
public void updateBalance(double bal ){

boolean isOK = new AmountValidator(){
public boolean checkAmount(double val){
return val >= 0.0;
}
}.checkAmount(bal);

//other irrelevant code
}
}

Which interface from java.util.function package should be used to refactor this code?

Select 1 option(s)

Consumer

Function

Predicate

Supplier

None

46.

Question: What can be inserted in the code below so that it will print 1 2 3?

class MyProcessor{
Integer value;
public MyProcessor(Integer value){
this.value = value;
}
public void process(){
System.out.println(value+" ");
}
}
public class TestClass {

public static void main(String[] args) {
List ls = Arrays.asList(1, 2, 3);

INSERT CODE HERE
}
}

Select 1 option(s)

ls.stream()
.map(x->MyProcessor::new(x))
.forEach(MyProcessor::process);

ls.stream()
.map(MyProcessor::new)
.forEach(MyProcessor::process);

ls.stream()
.forEach((x)->process( MyProcessor::new ));

ls.stream()
.forEach(x->MyProcessor::new);

None

47.

Question: 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 you the map of all the genres and the number of movies belonging to each genre?

Select 1 option(s)

None

48.

Question: Consider the following code:

import java.util.concurrent.*;

public class ThreadPoolTest {
public static void main(String[] args) {
Runnable r = ()-> System.out.println("In Runnable");
Callable c = ()-> { System.out.println("In Callable"); return 0; };
var es = Executors.newCachedThreadPool();

//INSERT CODE HERE

es.shutdown();

}

}

What can be inserted in the above code so that both - Runnable r and Callable c - will be executed?

Select 1 option(s)

es.submit(c);
es.submit(r);

es.execute(c);
es.execute(r);

es.add(c);
es.add(r);

Future< Integer > fi1 = es.submit(c);
Future< Integer > fi2 = es.submit(r);

Future< Integer > fi1 = es.submit(c);
Future< Object > fi2 = es.submit(r);

None

49.

Question: What will the following code print?

List ls = Arrays.asList(1, 2, 3);
Function func = a->a*a; //1
ls.stream().map(func).peek(System.out::print); //2

Select 1 option(s)

Compilation error at //1

Compilation error at //2

149

123

It will compile and run fine but will not print anything.

None

50.

Question: Consider the following class and interface definitions (in separate files):

public class Sample implements IInt{
public static void main(String[] args){
Sample s = new Sample(); //1
int j = s.thevalue; //2
int k = IInt.thevalue; //3
int l = thevalue; //4
}
}
public interface IInt{
int thevalue = 0;
}

What will happen when the above code is compiled and run?

Select 1 option(s)

It will give an error at compile time at line //1.

It will give an error at compile time at line //2.

It will give an error at compile time at line //3

It will give an error at compile time at line //4.

It will compile and run without any problem.

None

51.

Question: Which line(s) of code in the following program will cause compilation errors?

public class TestClass{
var value = 0; //1
public static void main(var args[]) //2
{
var secondArg = Integer.parseInt(args[2]); //3
if( true == 2 > 10 ) //4
{
value = -10;
}
else{
value = secondArg;
}
for( ; value>0; value--) System.out.println("A"); //5
}
}

Select 3 option(s)

52.

Question: What will the following code print when run?

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

public class TestClass
{
public static void main(String[] args)
{
double amount = 123456.789;
Locale fr = new Locale("fr", "FR");
NumberFormat formatter = NumberFormat.getInstance(fr);
String s = formatter.format(amount) ;
formatter = NumberFormat.getInstance();
Number amount2 = formatter.parse(s);
System.out.println( amount + " " + amount2 );
}
}

Select 1 option(s)

It will always print two equal numbers.

It will always print two unequal numbers.

It will not compile.

It will throw an exception at runtime.

None of these.

None

53.

Question: Assuming that getValue returns an int, which of the following options can be used in the code below:

int x = getValue();
String s = INSERT CODE HERE

Select 2 option(s)

switch(x){
case 0 -> "Zero";
case 1 -> "One";
default -> "Invalid";
};

switch(x){
case 0 -> return "Zero";
case 1 -> return "One";
default -> return "Invalid";
};

switch(x){
case 0 -> yield "Zero";
case 1 -> yield "One";
default -> yield "Invalid";
};

switch(x){
case 0 -> "Zero";
case 1 -> "One";
default -> {
yield "Invalid";
}
};

switch(x){
case 0 -> "Zero";
case 1 -> "One";
};

switch(x){
case 0 -> "Zero";
case 1 -> "One";
default -> {
return "Invalid";
}
};

54.

Question: What will the following code print?

class Test{
public static void main(String[] args){
int k = 1;
int[] a = { 1 };
k += (k = 4) * (k + 2);
a[0] += (a[0] = 4) * (a[0] + 2);
System.out.println( k + " , " + a[0]);
}
}

Select 1 option(s)

It will not compile.

4 , 4

25 , 25

13 , 13

None of the above.

None

55.

Question: Which of the following method(s) of java.util.stream.Stream interface is/are used for reduction?

Select 2 option(s)

collect

count

distinct

findAny

findFirst

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