Java Quiz 1: 26 October 2025 (September 2025 term)

1class Demo {
2    public void alpha(int n) {
3        if (n > 0) {
4            beta(n - 1);
5        }
6    }
7    public void beta(int n) {
8        if (n > 0) {
9            gamma(n - 1);
10        }
11    }
12    public void gamma(int n) {
13        if (n > 0) {
14            gamma(n - 1);
15        }
16    }
17}
18
19
20class TestStack {
21    public static void main(String[] args) {
22        Demo d = new Demo();
23        d.alpha(3);
24    }
25}

1public class ArraySquare {
2    public static int[] square(int[] a){
3        for(int i = 0; i < a.length; i++){
4            a[i] = a[i] * a[i];
5        }
6        return a;
7    }
8    public static void main(String[] args) {
9        int[] arr = {2,3,4};
10        int[] b = square(arr);
11        System.out.println(arr[1] + b[2]);
12    }
13}

1class Book {
2    private String title;
3    private String isbn;
4
5    //constructor to initialize the instance variables
6
7    public boolean equals(Object obj) {
8        // CODE BLOCK
9    }
10}
11
12public class Test {
13    public static void main(String[] args) {
14        Book[] library = {
15            new Book("Effective Java", "111"),
16            new Book("Clean Code", "222"),
17            new Book("Design Patterns", "333")
18        };
19
20        Book target = new Book("Clean Code", "222");
21        boolean found = false;
22
23        for (int i = 0; i < library.length; i++) {
24            if (library[i].equals(target)) {
25                found = true;
26                break;
27            }
28        }
29
30        if (found)
31            System.out.println("Book Found");
32        else
33            System.out.println("Book Not Found");
34    }
35}