A C++ program that uses function prime() for testing prime. Function should take integer argument and return Boolean value.

PrimeNumberUsingFunction.cpp

#include<iostream>
#include<conio.h>

using namespace std;

bool prime(int n);

int main()
{
 int n;
 cout<<"Enter any number : ";cin>>n;
 if(prime(n)==1)
     cout<<n<<" is a prime number.";
 else
     cout<<n<<" is not a prime number.";
 getch();
 return(0);
}

bool prime(int n)
{
 if(n==0||n==1||n==2)
     return(0);
 else
     {
   for(int i=2;i<=(n/2);i++)
   {
    if(n%i==0)
        return(0);
   }
   return(1);
 }
}