Passing value to a C++ function

Question

I've been using global variables up until now. I just remembered that it's not a good practice. So, is there any way I can change this? Should I pass the variables as value or reference?

This is the code https://pastebin.com/JZaaR2Qd

using namespace std;

string user_name;
string str_age;
unsigned short int user_age;
char yes_no_prompt;

void user_biodata_input()
{
    cin.clear();
    cout << "Name : ";  getline(cin >> ws, user_name);
    cout << "Age : "; getline(cin, str_age); //taking age as a string
    stringstream(str_age) >> user_age ; //extract int from a string

    //Check if user input is not numeric, if so, repeat
    while (cin.fail()) {
        cin.clear();
        cin.ignore(numeric_limits<streamsize>::max(), '\n');
        cout << "Input invalid! Please re-enter your age in numeric..." << endl;
        cin >> user_age;
    }
}

int main()
{
    //Speed up cin and cout
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    //Start
    cout << "Hi User, my name is Sirius. I'm your Digital Guidance (DG), nice to meet you..." << endl;
    cout << "Please provide your data..." << endl;
    user_biodata_input();

    show_user_biodata();

    while (yes_no_prompt == 'N' || yes_no_prompt == 'n')
    {
        cout << "Please re-enter your biodata..." << endl;
        user_biodata_input();
        show_user_biodata();
    }

Sure, you can pass by reference. What's your question? – John Zwinck Aug 06 '17 at 07:23 — John Zwinck, Aug 06 '17 at 07:23

score 0 · Accepted Answer · answered Aug 06 '17 at 07:42

Well, if you are going to use C++ you'd better try to leverage language capabilities, hence it's will much cleaner to present User class to encapsulate internal representation of user data you'd like to collect. For example:

class User {

    public:
        User(string name, unsigned short int age):_name(name),_age(age) {}

        bool confirm() {
            cin.clear();
            char yes_no_prompt;
            cout << "Thank you for providing your data...";
            cout << "\nPlease confirm your data...(Y/N)\n" << endl;

            //printing border
            cout << setfill('-') << setw(1) << "+" << setw(15) << "-" << setw(1) << "+" << setw(15) << "-" << setw(1) << "+" << endl;
            //printing student record
            cout << setfill(' ') << setw(1) << "|" << setw(15) << left << "Name" << setw(1) << "|" << setw(15) << left << "Age" << setw(1) << "|" << endl;
            //printing border
            cout << setfill('-') << setw(1) << "+" << setw(15) << "-" << setw(1) << "+" << setw(15) << "-" << setw(1) << "+" << endl;
            //printing student record
            cout << setfill(' ') << setw(1) << "|" << setw(15) << left << this->_name << setw(1) << "|" << setw(15) << left << this->_age << setw(1) << "|" << endl;
            //printing border
            cout << setfill('-') << setw(1) << "+" << setw(15) << "-" << setw(1) << "+" << setw(15) << "-" << setw(1) << "+" << endl;
            //printing student record

            cin >> yes_no_prompt;

            if (yes_no_prompt == 'Y' || yes_no_prompt == 'y')
            {
                cout << "\nThank you for giving cooperation...\nWe will now proceed to the academy..." << endl;
                return true;
            }
            return false;
        }
    private:
        string _name;
        unsigned short int _age;
};

Now you can implement function to collect user info:

User createUser()
{
    cin.clear();
    string user_name;
    string str_age;
    unsigned short int age;
    cout << "Name : ";  getline(cin >> ws, user_name);
    cout << "Age : "; getline(cin, str_age); //taking age as a string
    stringstream(str_age) >> age ; //extract int from a string

    //Check if user input is not numeric, if so, repeat
    while (cin.fail()) {
        cin.clear();
        cin.ignore(numeric_limits<streamsize>::max(), '\n');
        cout << "Input invalid! Please re-enter your age in numeric..." << endl;
        cin >> age;
    }
    return User(user_name, age);
}

Finally main will look something like this:

int main()
{
    //Speed up cin and cout
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    //Start
    cout << "Hi User, my name is Sirius. I'm your Digital Guidance (DG), nice to meet you..." << endl;
    cout << "Please provide your data..." << endl;

    User user = createUser();

    while (!user.confirm()) {
        user = createUser();

    }

    return 0;

}

Of course this is only a draft and suggestion, an alternative will be to make both of your function to receive parameters and being able to return values. While OOP approach IMO much cleaner.

Passing value to a C++ function

1 Answers1