Question

I am very new to C++, coming form Java and C. My book does not mention private functions and Google searches don’t turn up much. This should be trivial for me, but I can’t get it to work.

I have this code:

#ifndef RUNDATABASE_H
#define RUNDATABASE_H
#include <iostream>
#include <string>

class RunDatabase
{
    public:
        int main();
    protected:
    private:
        bool checkIfProperID(std::string);
};

#endif // RUNDATABASE_H

And in another file:

#include "RunDatabase.h"

int main()
{

    std::string id; // after this, I initialize id

    if(!checkIfProperID(id))
    {
        std::cout << "Improperly formatted student ID, must be numeric" << std::endl;
        break;
    }

}

bool RunDatabase::checkIfProperID(std::string id)
{
    return true;
}

I get this error: error: 'checkIfProperID' was not declared in this scope

Using MinGW g++ 4.4.1 on Windows 7 64 bit.

Thanks for any help.

Answer 1

checkIfProperID is a method of RunDatabase. This means you need to have a RunDatabase object in order to call checkIfProperID.

RunDatabase rd;
rd.checkIfProperID(id);

I don’t see why the other function is not in the scope.

The “scope” here is the class.

RunDatabase::checkIfProperID

Notice the scope-resolution operator ::. This means that the method belongs to the class, not global scope.