for loop not running in C plus plus program, without showing any error - CLOSED

Question

It is a very simple program and I have just started learning c++ but the for loop is not working in this program. can anyone tell me why the for loop in this c++ program is not running?

#include <iostream>
#include <string>
using namespace std;

class PrimeNo
{
    int a;
    int c;
public:
    // function to check prime number
    void chk_Prime(void)
    {
        cout << "Enter the number: " << endl;
        cin >> a;
        c=a/2; // to store the condition
        for (int i = 2; i < c; ++i)
        {
            if (a == 0 || a == 1) 
            {
                cout << "The number is not a prime number" << endl;
                break;
            }
            else if (a % i == 0) 
            {
                cout << "This number is not a prime number" << endl;
                break;
            }
            else //if upper conditions are false a number is a prime number
            {
                cout << "This number is a prime number" << endl;
                break;
            }
        }
    }
};

int main()
{
    PrimeNo Num;
    Num.chk_Prime();
    return 0;
}