read and store

[weirdo123]

i have a .txt file with format like this :

Student
1001
25 Bedford St. New York City, N.Y. 10014

Student
1002
125 Maiden Lane, 11th Floor New York, NY 10038

When i get student, i am supposed to store the number and also the address on the next line.

ifstream fin("list.txt")

string found = "Student";
string line, address;
int number;

while(fin >> line)
{
  if (line == found)
   {
      fin >> number;
      getline(fin, address);
   }
}

although the number is stored, but getline(fin,address) cant store the address.. what did i do wrong?

[lastchance]

Hello abcjune;

Your line 11 will read and store the number, but it won't remove the newline character from the stream afterwards. Thus, the following getline will read the rest of the line ... which is empty.

I think the 'ignore' statement below will work (100 is just allowing for a few blanks):

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

using namespace std;

int main()
{
   string found = "Student";
   string line, address;
   int number;


   ifstream fin( "list.txt" );

   while(fin >> line)
   {
      if (line == found)
      {
         fin >> number;      fin.ignore( 100, '\n' );
         getline(fin, address);
         cout << "Student number: " << number << "      Address " << address << endl;
      }
   }
}

An alternative approach might be:

#include<iostream>
#include<fstream>            
#include<sstream>
#include<string>        

using namespace std;

int main()
{
   string found = "Student";
   string line, address;
   string dummy;
   int number;


   ifstream fin( "list.txt" );

   while( getline( fin, line ) )                             // read a line from the file
   {
      if ( line.find( found) != string::npos )               // check if it contains the text in 'found'
      {
         stringstream ss( line );    ss >> dummy >> number;  // stream this line into a dummy variable and number
         getline( fin, address );                            // next line should be address
         cout << "Student number: " << number << "      Address " << address << endl;
      }
   }
}

Both produce

Student number: 1001      Address 25 Bedford St. New York City, N.Y. 10014
Student number: 1002      Address 125 Maiden Lane, 11th Floor New York, NY 10038

[weirdo123]

ohh so all along i was storing the empty spaces next to the student line?
i finally get it!! thanks alot!

[gunnerfunner]

OP: if the format of the file repeats itself throughout you can set up a (template) struct Student and read into and

print the struct directly. With template the number data-member could be string, double, unsigned int etc

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

template <typename T1, typename T2>
struct Student
{
    T1 _number;
    T2 _address;
};
template <typename T1, typename T2>
std::ostream& operator << (std::ostream& os, const Student<T1, T2>& s)
{
   os << "Student number: " << s._number << std::setw(8) << " Address: " << s._address << '\n';
   return os;
}

int main()
{
    std::fstream file("D:\\input.txt");
    using Student_T = Student<double, std::string>;
    Student_T s;
    std::vector<Student_T> vec;
    std::string line;
    while(file)
    {
        std::string line, dummy;
        getline(file, line);
        std::stringstream stream(line);
        stream >>dummy >> s._number;
        getline(file,s._address);
        if(file)
        {
            vec.push_back(std::move(s));
        }
        getline(file, dummy);
    }
    for (auto& elem : vec)
    {
        std::cout << elem;
    }
}