No arguments passed and no return value
#include <stdio.h>
void checkPrimeNumber();
int main()
{
checkPrimeNumber(); // argument is not passed
return 0;
}
// return type is void meaning doesn't return any value
void checkPrimeNumber()
{
int n, i, flag = 0;
printf("Enter a positive integer: ");
scanf("%d",&n);
for(i=2; i <= n/2; ++i)
{
if(n%i == 0)
{
flag = 1;
}
}
if (flag == 1)
printf("%d is not a prime number.", n);
else
printf("%d is a prime number.", n);
}