Put that cleanLine function back in

phone_numbers.cpp

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

//void function declaration
string cleanLine(string line);

int main( )
{
    //Declare variables to open files.
    char inFileName[16], outFileName[16];
    //Choose stream names for the input and output streams and
    //declare them as variables of type ifstream and ofstream respectively.
    ifstream inStream;
    ofstream outStream;

    // Inputs the input file name.
    cout << "Enter the input file name: ";
    cin >> inFileName;

    // Inputs the output file name.
    cout << "Enter the output file name: ";
    cin >> outFileName;

    // Opens the input file or displays an error message if unable to open.
    inStream.open(inFileName);
    if (inStream.fail())
    {
        cout << "Input file opening failed.\n";
        exit(1);
    }

    // Opens the output file or displays an error message if unable to open.
    outStream.open(outFileName);
    if (outStream.fail())
    {
        cout << "Input file opening failed.\n";
        exit(1);
    }

    //Declare variables.
    string line, convertedNum;

    //Loop through each line in the infile stream.
    while(getline(inStream, line))
    {
        // Output the line to console.
        cout << line;
        convertedNum=" ";

        // Find and replace all spaces
        line = cleanLine (line);

        //Looping through the line.
        for (int i=0; i<line.length(); i++)
        {
            //Displays only the first 7 digits
            convertedNum = convertedNum.substr(0,8);

            //Calling the switch statement
            switch(line[i])
            {
                case 'A':
                case 'B':
                case 'C':
                    convertedNum.append("2");
                    break;
                case 'D':
                case 'E':
                case 'F':
                    convertedNum.append("3");
                    break;
                case 'G':
                case 'H':
                case 'I':
                    convertedNum.append("4");
                    break;
                case 'J':
                case 'K':
                case 'L':
                    convertedNum.append("5");
                    break;
                case 'M':
                case 'N':
                case 'O':
                    convertedNum.append("6");
                    break;
                case 'P':
                case 'Q':
                case 'R':
                case 'S':
                    convertedNum.append("7");
                    break;
                case 'T':
                case 'U':
                case 'V':
                    convertedNum.append("8");
                    break;
                case 'W':
                case 'X':
                case 'Y':
                case 'Z':
                    convertedNum.append("9");
                    break;
                default:
                    convertedNum.append("*");
                    break;
                }

                if (convertedNum.size() == 4)
                {
                   convertedNum.append(" ");
                }
            }

        //Output to console.
        cout << convertedNum << "." << endl;

        //Send to outfile stream.
        outStream << convertedNum << endl;
    }
    return 0;
}

//Function to remove the spaces
string cleanLine(string line)
{
    string newLine;
    for(int i=0; i<line.size(); i++)
    {
        if (line[i] != ' ')
            newLine += line[i];
    }
    return newLine;
}