Question

I wrote the following code, and I was expecting to get
5
6
6
6, but I got 5 6 5 0 instead. It seems that “val” gets the reference correctly in the beginning, but then it gets lost. Does anybody know where is my mistake?

class Count {

    public:  
    void add() {  
    val++;
    }
    void print() {  
    cout << val  << endl;  
    }  
    Count(int c): val(c) {  
    }  
    private:  
    int &val;
};  

int main() {  

    int c = 5;  
    Count teste(c);  
    teste.print();  
    teste.add();  
    teste.print();  
    cout << c << endl;  
    teste.print();  
    return 0;  
}

Answer 1

Your constructor should take the parameter by reference, not by value.