Cannot convert 'std::string' to 'std::string*' for argument '2'

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Partially Fill an array from a file

i have no idea what this means. All of my variables line up. I cant seem to find any errors.

I also get the error error:no match for 'operator<<' in 'infile << names' if you repleace names with numoftoys its another error its giving me.

/***************************************************/
/* Author:     Sam LaManna                         */
/* Course:                                         */
/* Assignment: Program 6 Elves                     */
/* Due Date:   11/22/11                            */
/* Filename:   program6.cpp                        */
/* Purpose:    Write a program that will process   */
/*             the work done by santas elfs        */
/***************************************************/

#include <iostream>     //Basic input/output
#include <iomanip>      //Manipulators
#include <string>       //String stuff 
#include <fstream>      //File input/output

using namespace std;

void instruct ();     //Function Declaration for printing instructions 
void input (ifstream &infile, string names [50], int numoftoys[50], int &i);    //Function declaration for getting data from file

int main()
{

  string names [50] = { };       //Array for storing names
  int numoftoys [50] = { };      //Array for storing the number of toys made
  int i = 0;

  ifstream infile("eleves.dat"); //Opens input file "elves.dat"

  instruct();     //Function call to print instructions

  while (!infile.good())
    {
      input (infile, names[i] , numoftoys[i]);
      ++i;
    }

  cout << names << "\n" << "\n";

  cout << numoftoys << "\n" << "\n";




  return 0;
}




/***************************************************/
/* Name: instruct                                  */
/* Description: Prints instructions to user        */
/* Parameters: N/A                                 */
/* Return Value: N/A                               */
/***************************************************/

void instruct ()                                   
{
  cout << "\n" << "This program will calculate the toys made by santas elfs and assign" << "\n";
  cout << "a rating to each elf. It will also sort them and print average, min and max." << "\n";
  cout << "\n" << "Make sure you have a file named elves.dat in the same directory as";
  cout << "this porgram or you will recieve errors.";
  cout << "\n" << "\n";

  return;
}


/***************************************************/
/* Name: input                                     */
/* Description: Reads from file                    */
/* Parameters: N/A                                 */
/* Return Value: N/A                               */
/***************************************************/

void input (ifstream &infile, string names [50], int numoftoys[50], int &i)
{
  infile << names;
  infile << numoftoys;
  infile.ignore ('\n');

  return;
}

@Sam If I were you I would really not post question in whole like this...A google search of your prof **CSC 135 Lisa Frye** will give this as question as a hit !!! — parapura rajkumar, Dec 07 '11 at 21:00
@parapurarajkumar You realize that your comment will have the exact same effect, right? ;) — Bart, Dec 07 '11 at 21:08

Adrian Cornish · Answer 1 · 2011-12-07T21:10:00.263

3

Because you declared you function to take an array this degenerates into a pointer to the first element.

void input (ifstream &infile, string names [50], int numoftoys[50], int &i);

Here you are passing a single string and a single int to input() - because names[i] -is a single string in your array.

input (infile, names[i] , numoftoys[i]);

I suggest to change your function like this

void input(ifstream &infile, string &name, int &numoftoy)
{
  infile >> name;
  infile >> numoftoy;
  infile.ignore ('\n');

// return; no need return 
}

edited Dec 07 '11 at 21:10

answered Dec 07 '11 at 20:56

Adrian Cornish

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my program now gives me a "Bus Error (core dumped)" error when i try to run it – Sam LaManna Dec 07 '11 at 21:09
@Sam You are accessing memory you dont own. You probably exceeded the size of the array you allocated. – Adrian Cornish Dec 07 '11 at 21:12
The file only has 36 names and 36 numbers. how is that possible? – Sam LaManna Dec 07 '11 at 21:17
You are assuming that your reading code is working as you expect it too. You blindly access an element of your array without checking if 'i' is still within the size of your array. Try printing 'i' out on every loop iteration – Adrian Cornish Dec 07 '11 at 21:20

score 0 · Answer 2 · answered Dec 07 '11 at 20:56

You should iterate over the array of string. The reason you get error, because only operator<<(ostream& os, const string& str) is defined, not operator<<(ostream& os, const string* str).

A possible souliton would be iterating over the array with a for statement. Another (little bit more elegant) solution would be using std::for_each.

Cannot convert 'std::string' to 'std::string*' for argument '2'

2 Answers2