Question

I declare some variables:

int area_code;
int telephone_number;

when I get the input from user like:

cout << "Enter the area code";
cin >> area_code;
cout << "Enter your local telephone number";
cin >> telephone_number;

now when I want to display them, if their phone number is 6152222222 it should be displayed like:

615-222-2222

for the first part I can do like:

cout << area_code << "-";

but I don’t know how can I separate them with the dash for that one variable?

Answer 1

You can use math to calculate the area code and the local exchange code for your number:

• 6152222222 / 10000 drops the last four digits, giving you 615222
• Further dividing by 1000 gives you 615; taking the remainder of the division by 1000 gives you 222.

Please note that using an int to represent a telephone number limits your ability to store some more exotic phone numbers, such as 1-800-SOMETHING. Using a class encapsulating a string with additional validations may prove to be a better alternative:

class phone_number {
string phone;
public:
    phone_number(const string& p) {
        // validate p...
        if (p.size() != 10) {
            // Do something violent here...
            cerr << "The phone number is incorrect." << endl;
        }
        // Validate more things about the number before the assignment...
        phone = p;
    }
    friend ostream& operator<<(ostream &os, const phone_number& p);
};

ostream& operator<<(ostream &os, const phone_number& pn) {
    const string &p(pn.phone);
    os << "(" << p.substr(0, 3) << ")" << p.substr(3, 3) << "-" << p.substr(6);
    return os;
}

int main() {
    phone_number p = phone_number("6152784567");
    cout << p << endl;
    return 0;
}

This produces the expected output on ideone.