CODEWITHSUNDEEP
c++pass-by-reference
linofex
linofex

Reputation: 340

C++ references& and memory

I'm writing a code and I have a question about references&:

class A{
    private:
            int num;
    public:
            void set(const int& a){num = a;}
            void foo(){
                    int a = 4;
                    set(a);
            }
            void print(){
                    cout << num << endl;
            }

};  
int main(){
    A a;
    a.foo();
    a.print();
    return 0;
}

In this case, the variable a will be destroyed at the end of foo(). set take the reference, so the address of a and updates num. Therefore is this code wrong (num points to a deleted memory)? Or set, sets num with the value (not the address) of a?

I edit the code with a cout of address of a and num and they are different, so I think that num copies the value of a. If I run the code, all seems works, but I'm not sure.

Upvotes: 0

Views: 76

Answers (1)

Arnav Borborah
Arnav Borborah

Reputation: 11769

Your code isn't invalid, because the code num = a, takes a copy of a. Plus, set() is called BEFORE the objects memory is returned, so everyone has a copy, and nothing invalid happens. Also, remember, that num lasts while the class's instance lasts, so don't worry about deleted memory.

Upvotes: 2

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