why it shows twice

[raymjones]

void getfilename(string,string&);
int main()
{
  ifstream input;
  ofstream output;
  int number;
  int numberquestion;
  string inputfile,outputfile;//
  getfilename("input",inputfile);
  getfilename("output",outputfile);
  input.open(inputfile.c_str());
  output.open(outputfile.c_str());
  input>>number;
  while(!input.eof())
    {

      input>>numberquestion;
      output<<"full score: "<<numberquestion*2<<endl;
    }
  input.close();
  output.close();



return 0;

}
void getfilename(string filetype,string& filename)
{
  cout<<"enter name of"<<filetype<<"file\n";
  cin>>filename;
}

input is
4
20
output is
full score: 40
full score: 40
why does it show twice??

[Duthomhas]

Because you are looping on EOF. Don't do that.

You have to check whether the input operation failed immediately after attempting to input; you cannot wait. Combine lines 14..17 thus:

  while (input >> numberquestion)
    {
    output << "full score: " << (numberquestion * 2) << endl;
    }

Hope this helps.