Question

(C++) keep things as simple as possible. I would love a good starting point with hints to be able to finish it!

Write a function called is valid phone number that takes a phone number as an array of characters and its size, and returns true if the input array is a valid phone number, false otherwise. A phone number is valid only if it is of the following format: (uuu) uuu-uuuu where u is from ‘0’, ‘1’, ‘2’, etc. The parentheses, hypen and the space after ’)’ are necessary. Do not use the string or regex libraries

Answer 1

#include <iostream>

using namespace std;

//to check if u is in '0' to '9'

bool ir(char a)

{

    if(a>='0' && a<='9')

        return true;

    else

        return false;

}

//checking if given phone number is valid or not

//(uuu) uuu-uuuu (111) 985-1235

bool isvalid(char *str,int size)

{

    if(size!=14)

        return false;

    else

    {

        bool ans=false;

        if ((str[0]=='(') && (str[4]==')') && (str[5]==' ') && (str[9]=='-'))

        {

            if(ir(str[1]) && ir(str[2]) && ir(str[3]) && ir(str[6]) && ir(str[7]) && ir(str[8]) && ir(str[10]) && ir(str[11]) && ir(str[12]) && ir(str[13]) )

                ans=true;

        }

        return ans;

    }

}

int main()

{

    int size;

    cout << "Enter size: ";

    cin >> size;

    char str[size], ab[2];

    cin.getline( ab,2);

    cout << "Enter phone number: ";

    cin.getline( str,size+1);

    if(isvalid(str,size))

        cout<<"phone number is valid.";

    else

        cout<<"INVALID phone number";

    return 0;

}

//SAMPLE OUTPUT

//PLEASE LIKE IT RAISE YOUR THUMBS UP
//IF YOU ARE HAVING ANY DOUBT FEEL FREE TO ASK IN COMMENT SECTION