Searching and writing in a text file

[PKumar]

Create a textfile tele.data to accept 5 names and correspnding phone numbers (separated by a single space). Write a program to accept a number from the user and search the number to display the corresponding record.
#include<iostream>
#include<stdio>
#include<fstream>
ofstream f1;
ifstream f2;
using namespace::std;

void create()
{char w[100];
f1.open("tele.data");
for(int i=0;i<5;i++)
{gets(w);
f1<<w<<endl;}
f1.close();}

void seno()
{char w[100];long int no;
cout<<"Enter the number you want to search for";
cin>>no;
f2.open("tele.data");
while(f2)
{if(w[0]==no)
cout<<w<<endl;}
f2.close();}

void main()
{clrscr();
create();
seno();
getch();}

I have a problem with the search by number part. Please help. Thank you so much

[nuderobmonkey]

I suggest using a struct for storing the name and telNr, both as a std::string.

Here a whole example program. Especially take note how the operator << and >> can be overloaded for easily handling in- and output.

#include <iostream>
#include <fstream>
#include <string>
#include <vector>

struct Record
{
    std::string name;
    std::string telnr;
    
    Record() {}
    Record( std::string nam, std::string tel)
    : name(nam), telnr(tel)
    {}
};

std::istream& operator>>(std::istream& istr, Record& record)
{
    getline(istr, record.name);
    getline(istr, record.telnr);
    return istr;
}

std::ostream& operator<<(std::ostream& ostr, const Record& record)
{
    ostr << "name:  " << record.name << "\n"
         << "telnr: " << record.telnr << "\n\n";
    return ostr;
}

std::ofstream& operator<<(std::ofstream& of, const Record& record)
{
    of << record.name << "\n" << record.telnr << "\n";
    return of;
}

std::vector<Record> create(std::ostream& ostr, std::istream& istr)
{
     std::vector<Record> data_set;
     std::string name, telnr;
     for (int n=0; n<5; ++n)
     {
         ostr << "Enter name: ";
         std::getline(istr, name);
         ostr << "Enter telnr: ";
         std::getline(istr, telnr);
         ostr << "\n";
         data_set.push_back( Record(name,telnr) );
     }
     return data_set;
}
         
         
         
int main()
{
    std::string filename = "tele.data";

    // Getting names and telnrs from console input:
    std::vector<Record> data_set( create(std::cout,std::cin) );
    
    // Writing the data_set to a file:
    std::ofstream output_file(filename);
    if (!output_file)
    {
        std::cerr << "File " << filename << "couldn't opened!\n";
        return 1;
    }
    for (auto & record : data_set)
    {
        output_file << record;
    }
    output_file.close();
 
 
     
    // Open the data file:
    std::ifstream record_file(filename);
    if (!record_file)
    {
        std::cerr << "File " << filename << " not found!\n";
        return 1;
    }
    
    // Reading the data from file:
    data_set.clear();
    Record record;
    while ( record_file >> record)
    {
        data_set.push_back(record);
    }
  
    // Get the search name:
    std::cout << "Enter a number to search: ";
    std::string number_to_search;
    std::getline(std::cin, number_to_search);
    
    // Searching the number in the data_set
    {
        bool number_found = false;
        for (auto & record : data_set)
        {
            if (record.telnr == number_to_search)
            {
                number_found = true;
                std::cout << "Found for telnr " << number_to_search
                    << ":\n" << record.name << "\n";
                break;
            }
        }
        if (number_found == false)
        {
            std::cout << "No name for number " 
                << number_to_search << " found.\n";
        }
    }
    return 0;
}