没有重载的实例 function “getline”匹配参数列表——参数类型是：(std::ifstream,char)

Question

beginner c++ user here I have trying to take in lines from a file in put it into a string array. The file has each word on its own line. Whenever I tested the array it appeared it was loading each letter into the array. So it was chars instead each word as a string. The first thing in each file is a number that will be the array size. I was supposed to dynamically allocate the array's which I believe I did correctly. Any help is welcome. I am using VScode, and the issue that getline gives me is, no instance of overloaded function "getline" matches the argument list -- argument types are: (std::ifstream,char).

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

   using namespace std;

   int showMenuGetChoice();
   string createStringArray(int);
   void getInfoFromUser(string, string, int);
   void printStory(int, string, int);

   // Calls all the other functions to make a working Madlibs game. 
 int main ()
 {
    int UserChoice;

    ifstream QuestionFile;
    int arraySize;
    string Question;
    int test = 0;
    do {

    cout <<"Let's Play some Madlibs!!" << endl << endl;
    UserChoice=showMenuGetChoice();

    if (UserChoice == 1)
    {
        ifstream QuestionFile;
        QuestionFile.open("starWars.txt");
        QuestionFile >> arraySize;
        cin.ignore();

        string QuestionArray=createStringArray(arraySize);

        if(QuestionFile.is_open())
        {
            QuestionArray[arraySize];

            for(int i=0; i < arraySize; i++)
            {
                getline(QuestionFile, QuestionArray[i]);
            }
        }
        for(int i=0; i < arraySize; i++)
        {
            cout << QuestionArray[i] << endl;
        }

      }

// Takes in a integer and creates a array of that size. Dynamically allocates the array and returns a point to this array.
string createStringArray(int n)
{
    string*QuestionArray = new string[n];

    return *QuestionArray;
}

Answer 1

You're getting the error:

no instance of overloaded function "getline" matches the argument list -- argument types are: (std::ifstream,char).

Because of a problem with your "getline" call:

getline(QuestionFile, QuestionArray[i]);

std::getline accepts two parameters, a std::istream reference and a std::string reference. QuestionFile is an istream , so that's okay, however if you review the declaration of QuestionArray :

string QuestionArray=createStringArray(arraySize);

You should notice that QuestionArray is a variable of string type. I don't think this is what you intended. You should always carefully choose the type of variables you declare in C++, otherwise you are working against the type safety the compiler is trying to provide you with.

The i th element of the string QuestionArray is a char , not a string . This is the cause of the compiler error. You are trying to place the line into a single character element instead of a string.

Hopefully with the above explanation, the compiler message provided will make more sense now. It's providing the same information, just a little more condensed.

With that knowledge, lets address the createStringArray function:

string createStringArray(int n)
{
    string*QuestionArray = new string[n];

    return *QuestionArray;
}

You declare the function to return a single string, when I expect you want the function to return an sequence of strings. The correct way to return an sequence of strings is to use std::vector<std::string> , but if you must use risky, outdated, manual memory management you'll need to return a pointer to string, not a string from this function. With that knowledge you should be able to correct this function, the original QuestionArray variable type, and the compiler error should go away.