C++ unresolved external symbol

Question

Hi iam begginer at c++ i have class with static methods and i cant access them it throws me an error

    1>------ Build started: Project: CPractice, Confi         


        

Answer 1

You only declared name in the class, static variables need to be defined like so outside of the class:

string CPractice::name ="hello" ;

Answer 2

static string name;

As it is static, this line only declares name - you need to define it too. Simply place this below your class definition:

string CPractice::name;

If you end up moving your class to a corresponding header and implementation file, make sure you place this definition in the implementation file. It should only be defined in a single translation unit.

Answer 3

Since name is a static data member you should initialize it :) and not count on the default instance related constructor.

Add this after the class definitions (yep, I know its confusing since your member is a private one, but this is only an initialization) :

string CPractice::name;

Answer 4

I think you're trying to compile with gcc, when you should be compiling with g++. See What is the difference between g++ and gcc? for more on this.

You also need to add string CPractice::name; below your class definition.