How to handle the heap memory garbage?

Question

So I have this code where a PiggyBank object is created. There are three if statements depending on a choice. Since the keyword new allocates the object in the heap how should I properly manage the memory garbage,so when a different type of constructor is created, the old piggy bank will disappear, in the following code:

while(fChoice!=""){
        showFunctions();
        PiggyBank *pb;

        cin>>fChoice;
        cin.ignore(numeric_limits<streamsize>::max(),'\n');

        if(fChoice=="a") {
            pb = new PiggyBank();
        }
        else if (fChoice=="b"){
            cout<<"ENTER NAME:"<<endl;
            string name = "";
            cin>>name;
            pb = new PiggyBank(name);
        }
        else if (fChoice=="c") {
            cout<<"ENTER NAME:"<<endl;
            string name = "";
            cin>>name;
            cout<<"ENTER STARTING BALANCE:"<<endl;
            int startBalance = 0;
            cin>>startBalance;
            pb = new PiggyBank(name,startBalance);
        }
}

Answer 1

Don't use dynamic memory allocation in the first place. There is no apparent reason for it here:

while(fChoice!=""){
        showFunctions();
        PiggyBank pb;

        cin>>fChoice;
        cin.ignore(numeric_limits<streamsize>::max(),'\n');

        if(fChoice=="a") {
            pb = PiggyBank();
        }
        else if (fChoice=="b"){
            cout<<"ENTER NAME:"<<endl;
            string name = "";
            cin>>name;
            pb = PiggyBank(name);
        }
        else if (fChoice=="c") {
            cout<<"ENTER NAME:"<<endl;
            string name = "";
            cin>>name;
            cout<<"ENTER STARTING BALANCE:"<<endl;
            int startBalance = 0;
            cin>>startBalance;
            pb = PiggyBank(name,startBalance);
        }
}

(of course there is some dependence on the definition of PiggyBank here)

---

If you need to allocate dynamically (and you better have a very good reason for it), use std::unique_ptr which is a smart pointer that handles the deletion automatically for you when it goes out-of-scope or is assigned a new pointer.

while(fChoice!=""){
        showFunctions();
        std::unique_ptr<PiggyBank> pb;

        cin>>fChoice;
        cin.ignore(numeric_limits<streamsize>::max(),'\n');

        if(fChoice=="a") {
            pb = new PiggyBank();
        }
        else if (fChoice=="b"){
            cout<<"ENTER NAME:"<<endl;
            string name = "";
            cin>>name;
            pb = new PiggyBank(name);
        }
        else if (fChoice=="c") {
            cout<<"ENTER NAME:"<<endl;
            string name = "";
            cin>>name;
            cout<<"ENTER STARTING BALANCE:"<<endl;
            int startBalance = 0;
            cin>>startBalance;
            pb = new PiggyBank(name,startBalance);
        }
}

(requires #include<memory> )