How to create a global variable

cpp Portugal
  • 14 years ago


    I need really need help, I can not figure how to create a global variable that can be changed and used in
    several classes.

    I got many suggestions, but i can not make any of them work, always get errors...

    the last solution i tried was doing a "afile.h" where i put the variable using extern... but then i got "linking" errors...

    How can i solve this problem? I just need a boolean variable that can be "seen" anywhere...

    Please help me, if possible write down the code, because each word I write today as at least one error...

    Thank you in advance

  • 14 years ago

    Put The Variable in a .cpp File.


    in File4.cpp

    int gVariable=0;

    Then Create a Header File Containing the prototype
    In File4.h

    #ifndef _GLOBALVAR
    #define _GLOBALVAR

    // NOTE: This is NOT an actual variable,
    // it just helps the Linker Find the real variable in the cpp file.
    extern int gVariable;


    Now, add #include"File4.h" to the top of Every .cpp File that Needs to access the global Variable.

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