Re: Using Vectors in classes - public access

From:

Salt_Peter <pj_hern@yahoo.com>

Newsgroups:

comp.lang.c++

Date:

11 May 2007 12:05:45 -0700

Message-ID:

<1178910345.896626.93660@p77g2000hsh.googlegroups.com>

On May 11, 1:07 pm, Erik Wikstr=F6m <Erik-wikst...@telia.com> wrote:

On 2007-05-11 14:45, andrewmor...@aol.com wrote:

On May 11, 1:14 pm, Keith Halligan <keith.halli...@gmail.com> wrote:

On May 11, 12:57 pm, andrewmor...@aol.com wrote:

Hello,

I've got a VC++ project containing multiple classes and a main
function. In one of the class functions, it reads from a text file a=

places the data into a vector;
//
std::vector<std::vector<std::string> > applications (50,
std::vector<std::string>(12));
applications[colArr][0] = "Test1";
applications[colArr][1] = "Test2";
//
Which works fine for that classes function, however, I need for other
functions of the class, or potentially other classes to be able to
access the applications vector, most likely done through friend-ing
and inheritance.
I seem to be unable to get the applications vector to be publicly or
even privately declared inside the main class definition. I've tried
placing the vector definition in both sections, it causes
error C2059: syntax error : 'constant'
when I do.
Is there something I'm missing with this?

Thanks,
- Andy

-- Copy of UpdateFileArray.h ---
#ifndef _UPDATEFILEARRAY_H_
#define _UPDATEFILEARRAY_H_

#include <string>
#include <vector>

class UpdateFileArray
{
    std::vector<std::vector<std::string> > applications (50,
std::vector<std::string>(12));
public:
    void UpdateArray();
    void ArrayLookUp();
    friend class SearchVehicle;};

extern UpdateFileArray UFA;

#endif

Have a function in the vectors class to return a reference to the
vector.

One question though, why are you defining a vector of vector of
strings? Surely if you're just reading from a text file, a vector of
std::strings will be more than sufficent.- Hide quoted text -

- Show quoted text -

Hm, I'm a bit puzzled, what do you mean, return a reference to the
vector?

Something like this:

class UpdateFileArray
{
typedef Apps std::vector<std::vector<std::string> >;

typedef [source] [target], you got it backwards

Apps applications (50, std::vector<std::string>(12));

This is C++, not Java, definitions go either in a ctor definition's
body, that ctor's init list or in a function definition.
Definitions go with definitions.
You aren't allowed to define members in a class declaration.
A declaration is for declarations.

class N
{
  int n; // int n = 0; is illegal
  N(); // also a declaration
  void foo(); // a declaration
};

// a ctor *definition* with an init list
N::N() : n( 0 ) { }

// this is a definition:
void N::foo() { }

public:
   void UpdateArray();
   void ArrayLookUp();
   Apps& getArray() { return applications; }
   const Apps& getArray() { return applications; }
   friend class SearchVehicle;

};

--
Erik Wikstr=F6m