Input from file

[Ellisande]

How do I write it so if I have ifstream file("file.txt") that has rows of characters like

60
REGULAR NONE
GREEN BEGIN
REGULAR NONE
REGULAR NONE
GREEN END

that I can read one line at a time and do whatever I need with it.

[Geard2]

Here a link that will help with explainiations:

http://www.cplusplus.com/doc/tutorial/files.html

// reading a text file
#include <iostream>
#include <fstream>
#include <string>
using namespace std;

int main () {
  string line;
  ifstream myfile ("example.txt");
  if (myfile.is_open())
  {
    while (! myfile.eof() )
    {
      getline (myfile,line);
      cout << line << endl;
    }
    myfile.close();
  }

  else cout << "Unable to open file"; 

  return 0;
}

The key here is the getline() function that reads each line at a time. You can use the getline() function to read each line, and you can also specify delimiter (some type of punctuation i.e: ; . , to stop reading that line and to move to the next line). The general syntax for it is getline(cin, s) where "s" is a string type ( http://www.cppreference.com/wiki/string/getline )

[Ellisande]

Haha, not even a minute before you replied I found that little section both on that website and in my textbook. Thank you for the help though.

The only problem I seem to have with this is it reads the lines as a string. Is there a function in <string> that allows me to convert a string to an integer?

[VernonDozier]

Haha, not even a minute before you replied I found that little section both on that website and in my textbook. Thank you for the help though.

The only problem I seem to have with this is it reads the lines as a string. Is there a function in <string> that allows me to convert a string to an integer?

Not that I know of in the string library, but you can convert the string to a C-String and use atoi from cstdlib :

string aString = "12345";
    int anInt = atoi (aString.c_str ());
    cout << anInt << endl;