Reading from text file into array
 

Hi i'm pretty new to C++ (well very new!) and i need to read the information from a text file into an array. The kind of data i'll be using is a simple list of names. This is my first attempt at;

#include <iostream>

#include <fstream>

#include <string>

using namespace std;



int main () 

{

  string array[5];                          // creates array to hold names

  short loop;                               //short for loop for input

  short loop2;                               //short for loop for output

  string line;                              //this will contain the data read from the file

  ifstream myfile ("example.txt");          //opening the file.

  if (myfile.is_open())                     //if the file is open

  {

    while (! myfile.eof() )                 //while the end of file is NOT reached

    {

      getline (myfile,line);                //get one line from the file

      cout << line <<  endl;                //and output it

        for (loop=0; loop<5;loop++)         //criteria for input loop (as array 0-5)

      {

      array[loop]=line;                     //output loop statement

      };

        for (loop2=0; loop2<5;loop2++)      //criteria for output loop (as array 0-5)

      {

      cout << array[loop2];                     //loop statement

      };

    }

    myfile.close();                         //closing the file

  }

  else cout << "Unable to open file";       //if the file is not open output 

  system("PAUSE");

    



       system("PAUSE");

  return 0; 

}

The data appears in a file that looks like this:
john
dave
paul
jack
adam

Thanks for your time.

Re: Reading from text file into array
 

Use [ code ] [/ code ] (without spaces) tags to post your code.

Is this what you want....
You can simultaneously read line and put it into array[] and line, so you dont need two loops.

#include <iostream>

#include <fstream>

#include <string>

using namespace std;



int main ()

{

    string array[5]; // creates array to hold names



    short loop=0; //short for loop for input



    string line; //this will contain the data read from the file

    ifstream myfile ("example.txt"); //opening the file.

    if (myfile.is_open()) //if the file is open

    {

        while (! myfile.eof() ) //while the end of file is NOT reached

        {

            getline (myfile,line); //get one line from the file

            array[loop] = line;

            cout << array[loop] << endl; //and output it

            loop++;

        }

        myfile.close(); //closing the file

    }

    else cout << "Unable to open file"; //if the file is not open output



    system("PAUSE");

    return 0;

}

Re: Reading from text file into array
 

Thats it! Thanks alot Vishesh!

Re: Reading from text file into array
 

Problem #1:

while (! myfile.eof() )     //while the end of file is NOT reached

See this (.eof() is identical to feof()


Problem #2:

system("PAUSE");

See this

Re: Reading from text file into array
 

Vishesh, like Walter said, don't use EOF or you just end up writing an additonal condition to prevent the fetching of the last record, one too many times.

Instead use, while ( getline (file_stream, my_string ).good () )

And as for system ( "PAUSE" ) read the article posted.

Re: Reading from text file into array
 

#include <iostream> //For Input/Output

#include <fstream> //For File Input/Output

#include <string> //For Saving The Line Into The Array

using namespace std;

int main ()

{

        string array[5]; //Array to save the line on

        int loop=0; //Index of array

        int loop2;

        string line; //The line taken from the *.txt source

        ifstream myfile ("example.txt"); //To read from the *.txt File

        if (myfile.is_open()) //Checking if the file can be opened

        {

                while (! myfile.eof() ) //Runs while the file is NOT at the end

                {

                        getline (myfile,line); //Gets a single line from example.txt

                        array[loop]=line; //Saves that line in the array

                        loop++; //Does an increment to the variable 'loop'

                }

                myfile.close(); //Closes the file

        }

        else cout << "Unable to open file"<<endl; //Gives that sentence if the file can't be opened

        for(loop2=0;loop2<=loop;loop2++) //For loop make to cout the lines stored

                cout<<array[loop2]<<endl;    //inside of the variable 'array'

        return 0;

}

Your code made the 5 lines as output on the command prompt, but only the first line was saved in the variable array.

My code as I edited yours, saves the 5 lines from the file into the array and then it outputs them. Hope you benefit from this.

=EDIT= I'm sorry, I didn't see that you posted a corrected code before me. I didn't continue the rest of the thread. So sorry :)