Programming Example
Using switch statement, write a menu driven program to:
Study this program carefully to understand the logic, output, and explanation in a structured way.
Using switch statement, write a menu driven program to:
(i) To find and display all the factors of a number input by the user ( including 1 and the excluding the number itself).
Example:
Sample Input : n = 15
Sample Output : 1, 3, 5
(ii) To find and display the factorial of a number input by the user (the factorial of a non-negative integer n, denoted by n!, is the product of all integers less than or equal to n.)
Example:
Sample Input : n = 5
Sample Output : 5! = 1*2*3*4*5 = 120
For an incorrect choice, an appropriate error message should be displayed.
import java.util.Scanner;
public class RAnsariMenu
{
public static void main(String args[]) {
Scanner in = new Scanner(System.in);
System.out.println("1. Factors of number");
System.out.println("2. Factorial of number");
System.out.print("Enter your choice: ");
int choice = in.nextInt();
int num;
switch (choice) {
case 1:
System.out.print("Enter number: ");
num = in.nextInt();
for (int i = 1; i < num; i++) {
if (num % i == 0) {
System.out.print(i + " ");
}
}
System.out.println();
break;
case 2:
System.out.print("Enter number: ");
num = in.nextInt();
int f = 1;
for (int i = 1; i <= num; i++)
f *= i;
System.out.println("Factorial = " + f);
break;
default:
System.out.println("Incorrect Choice");
break;
}
}
}First read the algorithm, then study the program code line by line. After that, compare the code with the output and finally go through the explanation. This approach helps learners understand both the logic and the implementation properly.
After understanding this example, try to rewrite the same program without looking at the code. Then change some values or logic and run it again. This helps improve confidence and keeps learners engaged on the page for longer.