//Topic07 Generic Programming P.4

class Pair<T> {
    public T first;
    public T second;

    public Pair() {
    }

    public Pair(T x1, T x2) {
        first = x1;
        second = x2;
    }

    @Override
    public String toString() {
        return "(1)" + first + " (2)" + second;
    }
}

public class Main {
    public static void main(String[] args) {
        System.out.println("Demo Pair (Objects)\n=====================");

        Pair<String> p0 = new Pair<String>();
        Pair<String> p1 = new Pair<String>("hello", "cheers");
        Pair<Object> p5 = new Pair<Object>(123, "cheers");

        System.out.println(p0); // (1)null (2)null
        System.out.println(p1); // (1)hello (2)cheers
        System.out.println(p5); // (1)123 (2)cheers

        System.out.println(p1.first.getClass().toString());
        System.out.println(p5.first.getClass().toString());
        System.out.println(p1.second.getClass().toString());
        System.out.println(p5.second.getClass().toString());
    }
}