Programming Concepts using Java Quiz 1: 23 February 2025 (January 2025 term)

1class ClassOne{
2    public void methodOne(){
3        // ...
4    }
5    public void methodTwo(){
6        // ...
7        methodOne();
8        // ...
9    }
10    public void methodThree(){
11        // ...
12        methodTwo();
13        // ...
14    }
15}
16class ClassTwo{
17    public static void main(String[] args){
18        // ...
19        ClassOne c = new ClassOne();
20        c.methodThree();
21    }
22}

1public class NumberEvaluation {
2    public static void main(String[] args) {
3        int number = 10;
4
5        do {
6            number--;
7        } while (number > 5);
8
9        switch (number) {
10            case 5:
11                System.out.println("Low");
12                break;
13            case 6:
14                System.out.println("Medium");
15                break;
16            default:
17                if (number > 6) {
18                    System.out.println("High");
19                } else {
20                    System.out.println("Unknown");
21                }
22                break;
23        }
24    }
25}

1class Fruits {
2    public Fruits() {
3        System.out.println("Fruit created!");
4    }
5    public void display() {
6        System.out.println("Fruits!");
7    }
8}
9class Grapes extends Fruits {
10    public Grapes() {
11        super();
12        System.out.println("Grape created!");
13    }
14    public void display() {
15        System.out.println("Grapes!");
16    }
17}
18public class Example {
19    public static void main(String[] args) {
20        Fruits a = new Grapes();
21        a.display();
22    }
23}

1interface Animal {
2    default void sound() {
3        System.out.println("Animal making sound");
4    }
5    void eat();
6}
7interface Mammal extends Animal {
8    default void sound() {
9        System.out.println("Mammal making sound");
10    }
11}
12class Dog implements Mammal {
13    public void eat() {
14        System.out.println("Dog eating");
15    }
16}
17public class Test {
18    public static void main(String[] args) {
19        Animal obj = new Dog(); // LINE 1
20        obj.sound(); // LINE 2
21        obj.eat();
22    }
23}

1class Player {
2    private String playerID;
3    private String teamName;
4
5    // Constructor to initialize instance variables
6
7    public boolean equals(Object obj) {
8        //CODE BLOCK
9    }
10}
11public class Test {
12    public static void main(String[] args) {
13        Player p1 = new Player("004", "Red");
14        Player p2 = new Car("004", "Red");
15        if (p1.equals(p2))
16            System.out.println("p1 and p2 are same");
17        else
18            System.out.println("p1 and p2 are different");
19    }
20}

1interface Vehicle {
2    default void drive() {
3        System.out.println("Vehicle is driving");
4    }
5}
6interface Fuel {
7    default void refuel() {
8        System.out.println("Vehicle is refueling");
9    }
10}
11class Car implements Vehicle, Fuel {
12    public void drive() {
13        System.out.println("Car is driving smoothly");
14    }
15}
16public class Test {
17    public static void main(String[] args) {
18        Vehicle v1 = new Car();
19        v1.drive();
20        v1.refuel();  // LINE 1
21    }
22}

1class Book{
2    String name;
3    String[] authors;
4
5    public Book(String nm, String[] a){
6        name = nm;
7        authors = a;
8    }
9    public Book(Book b){
10        this.name = b.name;
11        this.authors = b.authors;
12    }
13}
14public class Test{
15    public static void main(String[] args){
16        String[] authors = {"Tagore", "Narayan", "Vikram"};
17        Book b1 = new Book("Gita", authors );
18        Book b2 = new Book(b1);
19        Book b3 = b1;
20        b2.name = "Nirmala";
21        b2.authors[0] = "Laxmana";
22        System.out.println(b1.name + ", " + b1.authors[0]);
23        System.out.println(b2.name + ", " + b2.authors[0]);
24        System.out.println(b3.name + ", " + b3.authors[0]);
25    }
26}

1class Appliance {
2    public void turnOn() {
3        System.out.println("Turn on appliance");
4    }
5}
6class Fan extends Appliance {
7    public void turnOn() {
8        System.out.println("Turn on fan");
9    }
10    public void turnOn(int speed) {
11        System.out.println("Set fan speed to: " + speed);
12    }
13}
14class SmartFan extends Fan {
15    public void turnOn() {
16        super.turnOn();
17        System.out.println("Turn on smart fan with default settings");
18    }
19}
20public class Test {
21    public static void main(String[] args) {
22        Fan obj = new SmartFan(); // LINE 1
23        obj.turnOn(); // LINE 2
24        obj.turnOn(3); // LINE 3
25    }
26}

1class BankAccount {
2    private int accountId;
3    private static double interestRate = 3.5;
4    public BankAccount(int accId) {
5        accountId = accId;
6    }
7    public final double calculateInterest() {
8        return interestRate * 0.01;
9    }
10}
11class SavingsAccount extends BankAccount {
12    public SavingsAccount(int accountId) {
13        super(accountId);
14    }
15    public final double calculateInterest() { // LINE 1
16        return (interestRate + 0.5) * 0.01;                              // LINE 2
17    }
18}
19public class BankTest {
20    public static void main(String[] args) {
21        SavingsAccount s1 = new BankAccount(505);  // LINE 3
22        BankAccount b1 = new SavingsAccount(501);  // LINE 4
23        System.out.println(b1.calculateInterest());
24        System.out.println(s1.calculateInterest());
25    }
26}

1interface Flyable {
2    default void fly() {
3        System.out.println("Flyable: Flying");
4    }
5    void takeOff();
6}
7-------- CODE BLOCK ------------
8class Sparrow extends Bird {
9    public void takeOff() {
10        System.out.println("Sparrow taking off");
11    }
12}
13public class Test {
14    public static void main(String[] args) {
15        Flyable obj = new Sparrow();
16        obj.fly();
17        obj.takeOff();
18    }
19}

1interface OrderCallback {
2    void onOrderReady(String dish);
3}
4class Waitstaff implements OrderCallback {
5    public void orderDish(String dish) {
6        Chef c = new Chef(this); // LINE 1
7        c.prepareDish(dish);
8    }
9    public void onOrderReady(String dish) {
10        System.out.println("Waitstaff: " + dish + " served!")
11                                                              ;
12    }
13}
14class Chef {
15    private OrderCallback callback;
16    public Chef(OrderCallback cb) {
17        callback = cb;
18    }
19    public void prepareDish(String dish) {
20        System.out.println("Chef: Preparing " + dish + "...")
21                                                              ;
22        System.out.println("Chef: " + dish + " is ready.");
23        callback.onOrderReady(dish); // LINE 2
24    }
25}
26
27public class Restaurant {
28    public static void main(String[] args) {
29        Waitstaff s1 = new Waitstaff();
30        s1.orderDish("pasta");
31    }
32}

1interface PlaylistIterator {
2    public boolean hasNextSong();
3    public Object getNextSong();
4}
5abstract class Song {
6    public abstract void play();
7}
8class SongPlaylist {
9    public SongPlaylist() {
10        private final int count = 3;
11        private Track[] songs = {new Track("Song A"), new Track("Song B"),
12                                new Track("Song C")};
13    }
14    private class Track extends Song {
15        private String title;
16        public Track(String title) {
17            this.title = title;
18        }
19        public void play() {
20            System.out.println("Playing: " + title);
21        }
22    }
23    private class PlaylistIter implements PlaylistIterator {
24        private int currentIndex;
25        public PlaylistIter() {
26            // Constructor
27
28        }
29        public boolean hasNextSong() {
30            // Check if there is a next song
31        }
32        public Object getNextSong() {
33            // Return the next song
34        }
35    }
36    public PlaylistIterator getIterator() {
37        return new PlaylistIter();
38    }
39}
40public class PlaylistTest {
41    public static void main(String[] args) {
42        SongPlaylist playlist = new SongPlaylist();
43        PlaylistIterator iter = playlist.getIterator();
44        while (iter.hasnext()){
45            -----------------------; //LINE 1
46        }
47    }
48}

1class Appliance {
2    public void turnOn() {
3        System.out.println("Appliance is turned on");
4    }
5}
6class WashingMachine extends Appliance {
7    public void turnOn() {
8        System.out.println("Washing machine is turned on");
9    }
10    public void startWashCycle() {
11        System.out.println("Wash cycle starts");
12    }
13}
14public class TestAppliance {
15    public static void main(String[] args) {
16        Appliance obj = new WashingMachine();
17        obj.turnOn();
18        --------------------// LINE 1
19    }
20}

1interface ClaimEligibility {
2    void printEligibility();
3}
4class Insurance {
5    private int age;
6    public Insurance(int a) {
7        age = a;
8    }
9    public ClaimEligibility checkEligibility() {
10        if (age > 25)
11            return new EligibleForClaim();
12        return new NotEligibleForClaim();
13    }
14    private class EligibleForClaim implements ClaimEligibility {
15        public void printEligibility() {
16            System.out.println("Eligible for Insurance Claim");
17        }
18    }
19    private class NotEligibleForClaim implements ClaimEligibility {
20        public void printEligibility() {
21            System.out.println("Not eligible for Insurance Claim");
22        }
23    }
24}
25public class Test {
26    public static void main(String[] args) {
27        Insurance ins1 = new Insurance(20);
28        ---------------------------- // LINE 1
29
30    }
31}