Question

Write a simple telephone directory program in C++ that looks up phone numbers in a file containing a list of names and phone numbers. The user should be prompted to enter a first name and last name, and the program then outputs the corresponding number, or indicates that the name isn't in the directory. After each lookup, the program should ask the user whether they want to look up another number, and then either repeat the process or exit the program. The data on the file should be organized so that each line contains a first name, a last name, and a phone number, separated by blanks. You can return to the beginning of the file by closing it an opening it again.
Use functional decomposition to solve the problem and code the solution using functions as appropriate. Be sure to use proper formatting and appropriate comments in your code. The output should be clearly labeled and neatly formatted, and the error messages should be informative.

Please do not use any array or somthing complicated. Keep it simple

Below is my code so far:

#include<iostream>
#include<string>
#include<fstream>
using namespace std;

void directory(string, string);

int main()
{
   ifstream inFile;
   inFile.open("telephone_data.txt");
   string fname, lname;
   char choice;

   do
   {
       cout << "Enter first name " << endl;
       cin >> fname;

       cout << "Enter last name" << endl;
       cin >> lname;

       directory(fname, lname);
   } while (toupper(choice) == 'Y');

   inFile.close();
   system("pause");
   return 0;
}

void directory(string f, string l)
{
   string first, last, pnumber;

   ifstream inFile;
   inFile.open("telephone_data.txt");

   if (!inFile)
   {
       cout << "Error in opening the file." << endl;
       system("pause");

   }
   else
   {

       while (!inFile.eof())
       {
           inFile >> first >> last;
           if ((first == f) && (last == l))
               cout << "The number is: " << pnumber << endl;

           else
               cout << "No match" << endl;
       }
   }
   inFile.close();
}

Answer 1

See you must create the a telephone_data.txt where you store the directory and then make following for the program.

here is the CODE

#include <iostream>
#include<string>
#include<fstream>
using namespace std;
// you made this file for reading the directory first and last name and find number
void directory(string, string);
int main()
{
string fname, lname;
char choice;
do
{
cout << "Enter first name " << endl;
cin >> fname;

cout << "Enter last name" << endl;
cin >> lname;

directory(fname, lname);
cout<<"Do you want to continue (y/n):";
cin>>choice;
} while (toupper(choice) == 'Y');
return 0;
}
void directory(string f, string l)
{
string first, last, pnumber;

ifstream inFile;
inFile.open("telephone_data.txt");
   int flag=0;
if (!inFile)
{
cout << "Error in opening the file." << endl;
system("pause");

}
else
{
       //changed some codition
while (inFile >> first >> last >>pnumber)
{

if ((first == f) && (last == l)){
        cout << "The number is: " << pnumber << endl;
               flag=1;
       }

}
if(flag == 0){
        cout << "No match" << endl;
   }
}
inFile.close();
}