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import java.util.Scanner;

class NumberMenu {
    static boolean isPronic(int n) {
        for (int k = 0; k * (k + 1) <= n; k++) {
            if (k * (k + 1) == n)
                return true;
        }
        return false;
    }

    static boolean isNiven(int n) {
        int sum = 0, t = n;
        while (t > 0) {
            sum += t % 10;
            t /= 10;
        }
        return sum > 0 && n % sum == 0;
    }

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.println("1. Pronic number check");
        System.out.println("2. Niven numbers in a range");
        System.out.print("Enter your choice: ");
        int choice = sc.nextInt();
        switch (choice) {
            case 1:
                System.out.print("Enter a number: ");
                int n = sc.nextInt();
                if (isPronic(n))
                    System.out.println(n + " is a Pronic number");
                else
                    System.out.println(n + " is not a Pronic number");
                break;
            case 2:
                System.out.print("Enter the lower and upper limits: ");
                int lo = sc.nextInt(), hi = sc.nextInt();
                int count = 0;
                for (int i = lo; i <= hi; i++) {
                    if (isNiven(i)) {
                        System.out.print(i + " ");
                        count++;
                    }
                }
                System.out.println();
                System.out.println("Count: " + count);
                break;
            default:
                System.out.println("Wrong choice");
        }
    }
}

Compiled and run in Java 21 with each input on the right before it went on this page.

1. Pronic number check
2. Niven numbers in a range
Enter your choice: 1
Enter a number: 132
132 is a Pronic number

Enter your choice: 1
Enter a number: 140
140 is not a Pronic number

Enter your choice: 2
Enter the lower and upper limits: 40 70
40 42 45 48 50 54 60 63 70
Count: 9

Enter your choice: 5
Wrong choice

Check one by hand: 63 has digit sum 9, and 63 ÷ 9 = 7, so it is a Niven number. 44 has digit sum 8, and 44 is not a multiple of 8, so it is left out.

/*
 * Program : menu for Pronic and Niven numbers
 * Input   : a menu choice, then a number or two limits
 * Output  : the result of the chosen check
 * Method  : isPronic tries k(k+1) for k = 0, 1, 2 ...
 *           isNiven divides n by the sum of its digits
 */

Five lines that tell an examiner what the program does before they read a single loop. Each school may want its own layout; follow your teacher's.