Question

1) Create a main() method with a switch statement that calls either a sum() OR factorial() method, depending on what selection the user of the program makes - ask the user to enter a selection (with System.out.println()), create a Scanner then read the user's input with a call to Scanner next(), then call the appropriate method in a switch (the String that was read from the call to Scanner.next() should be what you use as your switch condition).

2) Create a method, sum(), to include a FOR loop that will :

Get a scanner and input a number from the keyboard in main(). The method will take one parameter and calculate the sum up to that number. For example, if you pass 5, it it will calculate 1+2+3+4+5 and will return it back to main() method.

3) Create another method, factorial(), and repeat what was done for the sum() method above but compute the product instead.

Answer 1

import java.util.Scanner;

public class SumFact {
   public static void main(String[] args) {
       Scanner sc = new Scanner(System.in);
       boolean flag=true;
       int ch=0,n;
       while(flag) {
           System.out.println("1 Sum");
           System.out.println("2 Fact");
           System.out.println("3 Quit");
           ch=sc.nextInt();
           if(ch==3) break;
           System.out.println("Enter number: ");
           n=sc.nextInt();
          
           switch(ch) {
           case 1:System.out.println("Sum : "+sum(n));break;
           case 2:System.out.println("Fact : "+fact(n));break;
           }
       }
       System.out.println("Thank you..!!");
   }

   private static int fact(int n) {
       int total=1;
       for(int i=1;i<=n;i++)
           total*=i;
       return total;
   }

   private static int sum(int n) {
       int total=0;
       for(int i=0;i<=n;i++)
           total+=i;
       return total;
   }
}

CIULLU JUHULL Luvun LULUI 1 Sum 2 Fact 3 Quit Enter number: Sum : 15 1 Sum 2 Fact 3 Quit Enter number: Fact : 120 1 Sum 2 Fact 3 Quit Thank you..!!

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