21312

[jonnin]

set up a boolean, eg
bool isvalid{true}; //until proven otherwise, the value is valid..
then loop until happy:
do
isvalid = true; //reset it each loop!
read a number
test it.
for each test, you want something like
isvalid = isvalid && testresult;
while(!isvalid); //loop until you get a valid number

if you want to get fancy you can skip tests once isvalid is false.

[AbstractionAnon]

jonnin gave you the outline of what you need to do.
Something like this:

#include <iostream>
#include <fstream>
#include <string>
//  #include<bits/stdc++.h> 

using namespace std;

bool isValid(const string& phone)
{
    const string areaCode[] = { "520", "620","405", "550", "650" };

    if (phone.length() != 10)
    {
        cout << "Invalid phone number  ," << endl;
        return false;
    }
    // only focus first tree numbers to identify it is in right area code
    string area_C = phone.substr(0, 3);
    // Use the find function to check if the code is valid
    if (find(begin(areaCode), end(areaCode), area_C) == end(areaCode))
    {
        cout << "( !!ERROR!! ,Wrong area code or Invalid phone Number ! ) \n ";
        return false;
    }
    //  Passed all tests
    cout << "The phone number is valid" << endl;
    return true;
}

int main()
{
    string phoneNumber;

    //Print the Company name
    cout << "********************************************************************\n";
    cout << "          X Y Z  Regular (wired) Telephone Service \n";
    cout << "*********************************************************************\n";

    cout << "Enter the your phone number: ";
    while (1)   //  Loop forever if not valid
    {
        // Let user enter their phone number         
        cin >> phoneNumber;
        if (isValid(phoneNumber))
            break;  //  break out of loop
        //  We've already displayed what is wrong
        cout << "Please re-enter your phone number" << endl;
    }
    //  Got a valid phone number, exit the program
    return 0;

}

[The Grey Wolf]

I guess another one got their answer and spannered the thread.

[mbozzi]

The question was essentially, "How do I handle user input during an interactive session?"