The IIT Madras BS Programming Concepts using Java (Java) Quiz 1 paper sat on 7 Jul 2024, in the May 2024 term: 15 questions for 100 marks in 120 minutes. Every question is below with its answer. Take it as a timed mock test to be marked, or read it through first.
Which of the following statements is/are correct about activation records?
Return value link points to the start of the previous activation record.
An activation record is pushed into the stack when a function is called, and is popped out when the function returns.
The variables present in every activation record in the stack are in scope and are accessible.
The variables present in the topmost activation record of the stack are in scope and are accessible.
Correct answers
An activation record is pushed into the stack when a function is called, and is popped out when the function returns.
The variables present in the topmost activation record of the stack are in scope and are accessible.
Match the following terms with their descriptions/properties.
1-B, 2-A, 3-C, 4-D, 5-E
1-A, 2-B, 3-D, 4-E, 5-C
1-C, 2-D, 3-B, 4-E, 5-A
1-D, 2-C, 3-E, 4-A, 5-B
Correct answer
1-C, 2-D, 3-B, 4-E, 5-A
Consider the Java code given below.
public class Test{ public static void main(String[] args){ int a[] = {10, 20}; int x = a[0]; for(int i : a){ switch(i){ case 10: x = x + 10; System.out.println(x); break; case 20: x = x + 20; System.out.println(x); break; default: System.out.println(x); } } }}What will the output be?
20
30
30
20
40
20
40
60
10
20
40
Correct answer
20
40
Consider the Java code given below.
interface Printer{ public default void print(){ System.out.println("Prints"); }}interface Scanner{ public default void scan(){ System.out.println("Scans"); }}class Device implements Printer, Scanner{ public void print(){ System.out.println("Color printing"); }}public class Test { public static void main(String[] args) { Printer p1 = new Device(); p1.print(); p1.scan(); //LINE 1 }}Choose the correct option.
Correct answer
Consider the Java code given below.
class Employee { public void performTasks() { System.out.println("Perform tasks"); }}class Manager extends Employee { public void plan() { System.out.println("Plan tasks"); }
public void monitor() { System.out.println("Monitor employees"); }}class DeliveryHead extends Manager { public void plan() { System.out.println("Plan delivery operations"); }}public class Test { public static void main(String[] args) { Manager obj = new DeliveryHead(); obj.performTasks(); // LINE 1 obj.monitor(); obj.plan(); // LINE 2 }}Choose the correct option.
Correct answer
Consider the Java code given below.
class Bird { private String species; private String color; public Bird(String species, String color) { this.species = species; this.color = color; } // ------- CODE SEGMENT ---------}public class Test { public static void main(String[] args) { Bird b1 = new Bird("Parrot", "Green"); Bird b2 = new Bird("Sparrow", "Brown"); System.out.println(b1 + "\n" + b2); }}Choose the correct option to fill in the CODE SEGMENT so that the output is:
Parrot : Green
Sparrow : Brown
Correct answer
Consider the Java code given below. Identify the correct statement to fill in the blank at LINE 1, such that the output is: Eligible for Diploma
interface Eligibility { void printEligibility();}class Student { private double cgpa; //Constructor to initialize instance variable public Eligibility checkEligibility() { if (cgpa > 6.0) return new Eligible(); return new NotEligible(); } private class Eligible implements Eligibility { public void printEligibility() { System.out.println("Eligible for Diploma"); } } private class NotEligible implements Eligibility { public void printEligibility() { System.out.println("Not eligible for Diploma"); } }}public class Test { public static void main(String[] args) { Student s1 = new Student(5.5); Student s2 = new Student(7.5); ----------------------------- //LINE 1 }}Correct answer
Consider the code given below that checks whether two phones are the same. Method equals is overridden to compare two Phone objects as follows.
If two phones have the same brand and imeiNumber, then they are the same.
class Phone { private String brand; private int imeiNumber;
// Constructor to initialize instance variables
public boolean equals(Object obj) { //CODE BLOCK }}public class Test { public static void main(String[] args) { Phone p1 = new Phone("Samsung", 123456); Phone p2 = new Phone("Samsung", 123456); if (p1.equals(p2)) System.out.println("p1 and p2 are same"); else System.out.println("p1 and p2 are different"); }}Choose the correct option(s) to fill in place of CODE BLOCK so that the output is:
p1 and p2 are same
Correct answer
Consider the Java code given below.
class TravelAgency{ String name; String[] destinations;
public TravelAgency(String n, String[] d){ name = n; destinations = d; } public TravelAgency(TravelAgency t){ this.name = t.name; this.destinations = t.destinations; }}public class Test{ public static void main(String[] args){ String[] d = {"Ooty", "Bali", "Thailand"}; TravelAgency t1 = new TravelAgency("RoamWorld", d); TravelAgency t2 = new TravelAgency(t1); t2.name= "ValleyTravel"; t2.destinations[0] = "Goa"; System.out.println(t1.name + "," +t1.destinations[0]); System.out.println(t2.name + "," +t2.destinations[0]); }}What will the output be?
Correct answer
Consider the Java code given below.
class Screen { void showContent() { System.out.println("Display on screen"); }}class TV extends Screen { void showContent() { super.showContent(); System.out.println("Display on TV"); } void showContent(String s) { System.out.println("Display on TV: " + s); }}class Monitor extends TV { void showContent() { super.showContent(); System.out.println("Display on monitor"); } void showContent(String s) { System.out.println("Display on monitor: " + s); }}class Test { public static void main(String[] args) { TV obj = new Monitor(); // LINE 1 obj.showContent(); obj.showContent("News"); // LINE 2 }}Correct answer
Consider the Java code given below.
1 interface Coolable {2 public void startCooling();3 public void stopCooling();4 }5 interface TemperatureAdjustable {6 public void adjustTemperature();7 default void displayTemperature() {8 System.out.println("Temperature is adjustable.");9 }10 }11 class AirConditioner implements Coolable, TemperatureAdjustable {12 public void startCooling() {13 System.out.println("Cooling started.");14 }15 public void stopCooling() {16 System.out.println("Cooling stopped.");17 }18 }Choose the correct option regarding the above code.
Correct answer
Consider the Java code given below.
interface Singable { default void sing() { System.out.println("Sings"); } public void perform();}abstract class Musician implements Singable { public void sing() { System.out.println("Sings song"); }}class LeadSinger extends Musician { public void perform() { System.out.println("Leads group"); }}public class Test { public static void main(String[] args) { Singable obj1 = new LeadSinger(); // LINE 1 Musician obj2 = new LeadSinger(); obj2.sing(); obj2.perform(); // LINE 2 }}Choose the correct option.
Correct answer
Consider the Java code given below.
class Player { private String name; private int jerseyNumber; public Player(String nm){ name = nm; } public Player(int number){ jerseyNumber = number; } public Player(String nm, int number) { name = nm; jerseyNumber = number; } public String toString() { return "Name: " + name + ", Jersey Number: " + jerseyNumber; }}
class Captain extends Player { private String team; // ------- CODE BLOCK --------- public String toString() { return super.toString() + ", Team: " + team; }}Choose the correct option to fill in place of CODE BLOCK to instantiate instance variables of class Captain
Correct answer
Consider the Java code given below.
interface Iterator { public boolean has_next(); public Object get_next();}abstract class Printable { public abstract void print();}class BankAccount extends Printable { private String accountName; private double balance; public BankAccount(String aN, double b) { //initialize accountname and balance } public void print() { System.out.println(accountName + ", " + balance); }}class BankAccountList { private final int limit = 3; private BankAccount[] list; public BankAccountList(BankAccount[] accounts) { this.list = accounts; } private class BankAccountIter implements Iterator { private int indx; public BankAccountIter() { //constructor } public boolean has_next() { //if next element available in list return true;else false } public Object get_next() { //return next element from list } } public Iterator getIterator() { return new BankAccountIter(); }}public class Test{ public static void main(String[] args) { BankAccountList.BankAccount[] accounts = { new BankAccountList.BankAccount("Priya", 500), new BankAccountList.BankAccount("Ravi", 1000), new BankAccountList.BankAccount("Suresh", 1500) }; BankAccountList bList = new BankAccountList(accounts); Iterator iter = bList.getIterator(); while(iter.has_next()) { ------------------; //LINE 1 } }}Identify the appropriate statement to fill in the blank at LINE 1, such that the output is:
Priya, 500
Ravi, 1000
Suresh, 1500
Correct answer
Consider the Java code given below.
class Appliance { private int code; private static double basePower = 100; public Appliance(int c) { code = c; } public final double electricityFare() { return basePower*2; }}class Cooler extends Appliance { public Cooler(int x) { super(x); } public final double electricityFare() { //LINE 1 return basePower*3; //LINE 2 }}public class Test { public static void main(String[] args) { Appliance d1 = new Cooler(101); // LINE 3 Cooler c1 = new Appliance(105); // LINE 4 d1.electricityFare(); c1.electricityFare(); }}Which of the following statements is FALSE?
Correct answer