cpp issues

This is a discussion on cpp issues within the C Programming forums, part of the General Programming Boards category; Hello Guru's. I'm comming from VB background so have nightmare to switch to C/C++ in rewriting of simple programs, actually, ...

  1. #1
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    cpp issues

    Hello Guru's.
    I'm comming from VB background so have nightmare to switch to C/C++ in rewriting of simple programs, actually, to start ith cpp.

    So, situation is:
    header il.h

    Code:
    int ReadIL(bool RW, long ILRecord, IL);
    struct ILRec
    {
        char myRowStr[30];
        int myRowInt;
        float myRowf;
        char myNextStr[300];
    }IL;
    then:
    file il.cpp

    Code:
    #include "il.h"
    #include <stdio.h>
    #include <string.h>
    
    int ReadIL(RW, ILRecord, IL)
        {
         int ILLength=sizeof(struct ILRec);
    
            FILE *f;
            f=fopen("junk.dat","wb+");
            if (ILRecord<1) ILRecord=1;
            if (!f) return 1;
              {
                fseek(f,(ILLength*(ILRecord-1)),SEEK_SET);
                if (RW)
                {
              //  strcpy(IL.myRowStr,"my string to file");
                fwrite(&IL, ILLength, 1, f);
                }
                else
                {
                fread(&IL, ILLength, 1, f);
                }
              }
             fclose(f);
             return 0;
        }
    In my main cpp program I have also included il.h
    and from there I call function like this:

    Code:
    long ILRecord=1;
    ReadIL(false, ILRecord, IL);
    And I get several errors during compiling
    C:\Users\John\Desktop\aaa\il.h|1|error: 'IL' has not been declared|
    C:\Users\John\Desktop\aaa\aaaMain.cpp||In member function 'void aaaFrame::OnbtnOpenClick(wxCommandEvent&)':|
    C:\Users\John\Desktop\aaa\aaaMain.cpp|344|error: cannot convert 'ILRec' to 'int' for argument '3' to 'int ReadIL(bool, long int, int)'|
    ||=== Build finished: 2 errors, 0 warnings ===|

    Purpose of wanted program is to chose a record in Main program (ILRecord) and to get required data in structure IL from function ReadIL from other file in same project.
    What do I do bad and how to get this to work?
    Please for recommendation at newbie level.

  2. #2
    C++ Witch laserlight's Avatar
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    Quote Originally Posted by nime
    I'm comming from VB background so have nightmare to switch to C/C++ in rewriting of simple programs, actually, to start ith cpp.
    Are you switching to C or C++? They are two different programming languages.
    C + C++ Compiler: MinGW port of GCC
    Version Control System: Bazaar

    Look up a C++ Reference and learn How To Ask Questions The Smart Way

  3. #3
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    First error says:
    il.h|1|error: 'IL' has not been declared|
    In il.h, you need to define IL at a variable type, so add the red bit below:
    Code:
    typedef struct ILRec
    {
        char myRowStr[30];
        int myRowInt;
        float myRowf;
        char myNextStr[300];
    }IL;

  4. #4
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    laserlight, I know that I work with file at C way and this is because of better simmilarity with my VB programs.

    Jamdog, donned, but now again this...


    C:\Users\John\Desktop\aaa\il.h|1|error: 'IL' has not been declared|
    C:\Users\John\Desktop\aaa\aaaMain.cpp||In member function 'void aaaFrame::OnbtnOpenClick(wxCommandEvent&)':|
    C:\Users\John\Desktop\aaa\aaaMain.cpp|345|error: expected primary-expression before ')' token|
    ||=== Build finished: 2 errors, 0 warnings ===

  5. #5
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    Ups, I added il.h to my main.h and only one error lefts:

    C:\Users\John\Desktop\aaa\il.h|1|error: 'IL' has not been declared|
    ||=== Build finished: 1 errors, 0 warnings ===|

    Obviously is needed to make IL "public", but how to do this?

  6. #6
    Registered User claudiu's Avatar
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    I suggest you start fresh, forget about VB, pick up a C book or tutorial and immerse yourself in a new world. Trying to adapt to writing in another language like you do in one you already know is most likely a futile exercise to begin with. The same goes with actual languages, you can't expect to apply what you know in English in order to learn German.
    Last edited by claudiu; 09-27-2010 at 05:08 AM.
    1. Get rid of gets(). Never ever ever use it again. Replace it with fgets() and use that instead.
    2. Get rid of void main and replace it with int main(void) and return 0 at the end of the function.
    3. Get rid of conio.h and other antiquated DOS crap headers.
    4. Don't cast the return value of malloc, even if you always always always make sure that stdlib.h is included.

  7. #7
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    So, If I want to learn german language I should first forget english?
    Mein Gott!

    Btw, we have here simple issue with propper organizing files in c++ project...

  8. #8
    Bored Programmer
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    The error itself tells you what is wrong... "IL undeclared". Why would it say this? It apears you declared IL so is anything ABOVE the declaration of IL that uses IL? Dunno if that will make all your problems go away, but I'm assuming the error you are getting is because of the function that is declared above IL and is told that it requires a IL as a parameter, but the compiler doesn't yet know what a IL is.

  9. #9
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    Lesshardtofind,
    I noticed that and moved declaration of function below struct, but error persist.

    Code:
    typedef struct ILRec
    {
        char myRowStr[30];
        int myRowInt;
        float myRowf;
        char myNextStr[300];
    }IL;
    int ReadIL(bool RW, long ILRecord, IL);
    Of course, I can't yet figure why error commes and what REALY, but when I read a file at same way in main module everything is ok, without error.
    Maybe somebody with more expirience on this things can know...

  10. #10
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    Code:
    int ReadIL(bool RW, long ILRecord, IL);
    Probably has something to do with that line.

    Code:
    int ReadIL(RW, ILRecord, IL)
    Is declared wrong too. You needs types and var names when declaring functions.
    Last edited by homer_3; 09-27-2010 at 07:48 AM.

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