wap a program to create menu by switch if we choose 1. factorial 2. odd even 3. prime or not prime 4. exit.

 

#include<stdio.h>

#include<conio.h>

#include<stdlib.h>

 main()

{

   int fact=1,i,a,no,choice,p=0;

   

   while (1)

   {

       printf("\n1 factorial");

       printf("\n2 odd even");

       printf("\n3 prime number or not");

       printf("\n4 exit");

       printf("\n select a opt ");

       scanf(" %d",&choice);

    switch(choice)

    {

        case 1 :

                 printf("enter any no.");

                 scanf(" %d",&no);

                 for(i=1;i<=no;i++)

                 {

                    fact*=i;

                 }

                 printf("your factorial is %d",fact);

                 break;

        case 2 :

                 printf("enter a no.");

                 scanf("%d",&no);

                 if(no%2==0)

                 printf("it is even no.");

                 else

                 printf("no. is odd");

                 break;

        case 3 :

                 printf("select a no.");

                 scanf("%d",&no);

                 for (a=1;a>=no;a++)

                 {

                    if (no%a==0)

                     {

                         p++;

                     }

                 }

                   if(p==2)

                    {

                       printf("%d is not a prime number",no);

                    }

                   else

                   {

                      printf("%d is a prime number",no); 

                   }

                   break;

        case 4 : exit (0) ;

        default : printf("u choose wrong");

     }

   }

}

output :

1 factorial 2 odd even 3 prime number or not 4 exit select a opt 1 enter any no.7 your factorial is 5040

1 factorial 2 odd even 3 prime number or not 4 exit select a opt 2 enter a no.23 no. is odd

1 factorial 2 odd even 3 prime number or not 4 exit select a opt3 select a no.23 23 is a prime number

1 factorial 2 odd even 3 prime number or not 4 exit select a opt 5 u choose wrong

1 factorial 2 odd even 3 prime number or not 4 exit select a opt 4