Thread: Calling a user-defined function in C++

  1. #1
    Registered User brianptodd's Avatar
    Join Date
    Oct 2002

    Calling a user-defined function in C++

    I am trying to call a function that I created and placed in a .h file. When the function is in my program, it works great. However, when I place the function in the .h file and call to it, I get "undefined reference" errors in the compile. I'm not certain of the syntax for defining a function in the .h file, which is probably the problem.

    I am looking for an example of a function call to a user-defined function and .h file.

    I am using TextPad to write the code and GNU to complile on a 2000 machine.

    Attached is a zip file with the program (cgrade.cpp), the .h file (myfuncts.h) and the cpp file for the .h file (myfuncts.cpp).

    Any help or suggestions would be greatly appreciated.



  2. #2
    Redundantly Redundant RoD's Avatar
    Join Date
    Sep 2002
    example, in example.h u have callme () function.

    so in your main .cpp:

    #include <example.h>

    in the code where u want it

    callme ();

    Thats what i do, in VC++

  3. #3
    Guest Sebastiani's Avatar
    Join Date
    Aug 2001
    Waterloo, Texas
    replace the top of your program file with:

    #include <iostream>
    #include "myfuncts.h"
    #include "myfuncts.cpp"
    #include <string>

    //double weighted_avg(double, double, double);
    //string letter_grade(double);

    The reason is that unless you compile "myfuncts.cpp" and then include the ".o" file in the build, you won't be able to reference the functions. Also, you can put the functions in the ".h" file instead, if you'd like.
    #include <cmath>
    #include <complex>
    bool euler_flip(bool value)
        return std::pow
            std::complex<float>(0, 1) 
            * std::complex<float>(std::atan(1.0)
            *(1 << (value + 2)))
        ).real() < 0;

  4. #4
    Registered User brianptodd's Avatar
    Join Date
    Oct 2002

    Thank you very much. It seems like such a simple solution now, but thank you. It's working just fine now.


Popular pages Recent additions subscribe to a feed

Similar Threads

  1. Message class ** Need help befor 12am tonight**
    By TransformedBG in forum C++ Programming
    Replies: 1
    Last Post: 11-29-2006, 10:03 PM
  2. Change this program so it uses function??
    By stormfront in forum C Programming
    Replies: 8
    Last Post: 11-01-2005, 07:55 AM
  3. errors initializing D3D
    By Vacation Guy in forum C++ Programming
    Replies: 3
    Last Post: 08-07-2005, 12:20 PM
  4. Please Help - Problem with Compilers
    By toonlover in forum C++ Programming
    Replies: 5
    Last Post: 07-23-2005, 10:03 AM
  5. Tab Controls - API
    By -KEN- in forum Windows Programming
    Replies: 7
    Last Post: 06-02-2002, 09:44 AM