Solved

unresolved external symbol "private: static char

Posted on 2001-09-10
2
1,500 Views
Last Modified: 2009-05-19
I have created an application consisting of 1 base class and a number of sub classes. The definition of the base class is like:
class StaticBase {
    static char myC;
  public:
    static void setMyC();
};
When linking the program with MS VC++ 5.0, I get this error:
StaticBase.obj : error LNK2001: unresolved external symbol "private: static char  StaticBase::myC" (?myC@StaticBase@@0DA)
What am I doing wrong?

0
Comment
Question by:arefe
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
2 Comments
 
LVL 6

Expert Comment

by:kotan
ID: 6469954
missing ; on the end of class declaration

class base {
   ...
};
0
 
LVL 1

Accepted Solution

by:
glebspy earned 100 total points
ID: 6470244
In c++, you must declare static data not only within the class itself but also outside.

This is the correct way to do it...

class StaticBase {
  static char myC;
public:
  static void setMyC();
};

char StaticBase::myC;
void StaticBase::setMyC(){...}



Don't worry.. myC is still private. But if you didn't include the line "char StaticBase::myC;" then *even members of StaticBase* (like setMyC()) wouldn't know what myC was, unless they were defined in class scope.

An alternative fix is therefore:

class StaticBase {
  static char myC;
public:
  static void setMyC(){
   //**DEFINE setMyC() HERE NOT OUTSIDE CLASS SCOPE**//
  }
};

0

Featured Post

Free Tool: Port Scanner

Check which ports are open to the outside world. Helps make sure that your firewall rules are working as intended.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

In days of old, returning something by value from a function in C++ was necessarily avoided because it would, invariably, involve one or even two copies of the object being created and potentially costly calls to a copy-constructor and destructor. A…
Many modern programming languages support the concept of a property -- a class member that combines characteristics of both a data member and a method.  These are sometimes called "smart fields" because you can add logic that is applied automaticall…
The goal of the video will be to teach the user the difference and consequence of passing data by value vs passing data by reference in C++. An example of passing data by value as well as an example of passing data by reference will be be given. Bot…
The viewer will be introduced to the member functions push_back and pop_back of the vector class. The video will teach the difference between the two as well as how to use each one along with its functionality.

738 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question