## C Programming

### Menu driven program to perform factorial, prime number, odd even check and exit the program

#### Objective

Write a menu driven proram which have the following options:

• Factorial of a number
• Prime or not
• Even or Odd
• Exit

#### Program

#include "stdio.h"
#include "math.h"
#include "stdlib.h"

int main() {
int ch;
int i,n,result;
double sqroot;
do {
printf("1. Factorial\n");
printf("2. Prime number\n");
printf("3. Even or odd\n");
printf("4. Exit\n");
scanf("%d",&ch);

switch(ch) {
case 1:
printf("Enter any number: ");
scanf("%d",&n);
for(i = 1, result = 1; i <= n; i++) {
result = result * i;
}

printf("Factorial of %d = %d\n",n,result);
break;
case 2:
printf("Enter any number: ");
scanf("%d",&n);
sqroot = sqrt(n);
result = 1;
for(i = 2; i <= sqroot; i++) {
if(n % i == 0) {
result = 0;
break;
}
}
if(result) {
printf("%d is a prime number\n",n);
}else {
printf("%d is not a prime number\n",n);
}
break;
case 3:
printf("Enter any number: ");
scanf("%d",&n);
if(n%2) {
printf("%d is odd\n",n);
}else {
printf("%d is even\n",n);
}
break;
case 4:
exit(0);
break;
}
} while(ch != 4);

return 0;
}

#### Output

-----------------------

1. Factorial
2. Prime number
3. Even or odd
4. Exit
Enter any number: 6
Factorial of 6 = 720
-----------------------

1. Factorial
2. Prime number
3. Even or odd
4. Exit
Enter any number: 13
13 is a prime number
-----------------------

1. Factorial
2. Prime number
3. Even or odd
4. Exit
Enter any number: 56
56 is even