Question

ok so this is what i have but I am getting an error says ‘complexReverseString’: identifier not found??? where am I going wrong I looked it over to no avail

#include <iostream>
#include <fstream>
#include <string>
using namespace std;

int main()
{
    ifstream input;
    string forward;

    cout << "Please enter a string to see its reverse. (Will display reverse twice)" << endl;
    input.open("information.txt");
    cin >> forward;
    //reverseString(forward, findStringSize(forward)); a function I'm not actually calling
    input >> forward;
    complexReverseString();

    input.close();


}
int complexReverseString(string userInput)
{
    string source(userInput);
    string target( source.rbegin(), source.rend() );
    cout << "The reversed string is " << target << endl;

    return 0;
}

Answer 1

You have to prototype complexReverseString() first before you call it.

Either do it in the source file before the main entry-point like this:

int complexReverseString(string userInput);
int main() { ... }

or do it in a separate header:

#ifndef COMPLEX_STR_HPP
#define COMPLEX_STR_HPP

int complexReverseString(string userInput);

#endif /* COMPLEX_STR_HPP */

/* int main.cpp */
#include "complex_str.hpp"

int main() { ... }

Secondly, you forgot to pass a parameter to the function:

 complexReverseString( /* parameter here */ );

 e.g
 complexReverseString(forward);

Thirdly, since you did not change the string in complexReverseString() I suggest taking a const string, and perhaps a reference to the string:

int complexReverseString(const string& userInput);