Using a string in a class?

[ab00120]

Hi there,

At university I learnt Fortran to an adequate level for simple programs and as I enjoyed it i looked towards trying to learn C++. Up to now its been very slow but progressing, however i seem to have hit a bit of a brick wall.

From just material on the internet I have found this one of the best and most friendly websites so was hoping to hopefully get a bit of help without looking too stupid lol.

Without going off on one im basically trying to define a string that is part of a class and then bring it into the main function for output. This may seem strange but I think it is a requirement for my program which at the end will span a fair few source files.

Anyway this is my code at present:

#include "stdafx.h"
#include <iostream>
#include <string>
using namespace std;
 
class test 
{
public:
	void write(std::string);
};
 
void test::write(std::string name)
{
	name = "HELLO";
}


int main ()
{
	  test A;
	  cout << A.write(name) << endl;
	  return 0;
}

I am revcieving an error:

error C2065: 'name' : undeclared identifier

Do I require the use of pointers perhaps?

I hope this is enough for someone to understand.

Thank you very much in advance for your time in looking at this,

Andy

[Clinton Portis]

Try this and see if it works for ye'...

std::string& write();

std::string& test::write()
{	
          std::string *name = "HELLO";
          return name:
}

[ab00120]

Hi mate,

Thanks for your reply. I have implemented the code as shown below but for some reason it still comes up with an error or two although they do look a lot more promising though lol:

#include "stdafx.h"
#include <iostream>
#include <string>
using namespace std;
 
class test 
{
public:
	std::string& write();
};
 
std::string& test::write()
{
	std::string *name = "HELLO";
	return name;
}


int main ()
{
	  test A;
	  cout << A.write() << endl;
	  return 0;
}

errors:
1)error C2440: 'initializing' : cannot convert from 'const char [6]' to 'std::string *'
2)error C2440: 'return' : cannot convert from 'std::string *' to 'std::string &'

Sorry if im being a numpty and maybe misinterpreted what you where saying!

[mrnutty]

In your first post you haven't defined a name within scope. I think what
you are trying to is something like this :

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

class Test
{
    string name;
    public :
     Test(string str) { name = str; }
     Test() { name = "NULL"; }
     void setName(string str) { name = str; }
     string getName() { return name; }   
};

int main()
{
    Test test1("Greatest 4 eva");
    cout << test1.getName();
    test1.setName("4 eva the greatest");
    cout << test1.getName();
  return 0;
}

[Ancient Dragon]

You can do this

class test 
{
public:
    std::string write();
};
 
std::string test::write()
{
	std::string name = "HELLO";
	return name;
}


int main ()
{
	  test A;
	  cout << A.write() << endl;
	  return 0;
}

[ab00120]

Hi,

Thanks for the above, it's useful for me however I dont think I have managed to explain myself correctly so sorry for that.

Essentially what I am trying to do is crete a string that wont ever change in a class that can later be passed onto the main function. I know this may sound odd but at the end I would like to be passing a number of constant strings to the main.

eg.

class
{
//declaration of string
}

string
{
//definition of the string eg hello
}

main
{
//string passed into main
}

The way my program is currently written wont really accept a diferent strategy without a major overhaul which im not too keen to do considering my control of the c++ language.

I hope this clears my intentions up and sorry if ive been misleading.

Thanks again,

Andy

[ab00120]

Hi again,

I think I posted just after you posted Ancient Dragon.

Your code above has worked perfectly.

Thank you for all your quick replies, is very much appreciated.