easy question, i think...

This is a discussion on easy question, i think... within the C Programming forums, part of the General Programming Boards category; Hi, I have this code: Code: int main() { int a = 1; test(); return a; } void test() { ...

  1. #1
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    easy question, i think...

    Hi,

    I have this code:

    Code:
    int main()
    {
    int a = 1;
    test();
    return a;
    }
    
    void test()
    {
    int b;
    int c = 4;
    b = c + a;
    }
    I know this isn't right, so how do you make it right without having to change much of the concept? I simplified it from a more tedious code. Thanks in advance.

  2. #2
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    Code:
    int main()
    {
    int a = 1;
    test(a);
    return a;
    }
    
    void test() /* can you figure out yourself how to access the 'a' passed from main? */ 
    {
    int b;
    int c = 4;
    b = c + a;
    }

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    hey, thanks for the quick reply...

    I understand that you can pass a variable from main... is there any other way besides that?

  4. #4
    Woof, woof! zacs7's Avatar
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    A global variable?

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    Quote Originally Posted by zacs7 View Post
    A global variable?
    That sounded to me as if you cried out loud saying:
    ESBO ! ! ! !

    PS: Fond memories of him

  6. #6
    Woof, woof! zacs7's Avatar
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    Another way if you knew what was going on would be inline assembly

    Neither is a good idea in this case.

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    me-eating-rice, are you from India?
    Is your rice-eating over?

    me-not-eating-rice

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    Code:
    #include <stdio.h>
    
    int a = 1;
    
    int test()
    {
            return (4 + a);
    }
    
    int main(void)
    {
            printf("&#37;d\n", test());
            return test();
    }
    or

    Code:
    #include <stdio.h>
    
    #define a 1
    
    int test()
    {
            return (4 + a);
    }
    
    int main(void)
    {
            printf("%d\n", test());
            return test();
    }

  9. #9
    C++まいる!Cをこわせ!
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    I think a define is more preferable here. Or const int (though that would be more appropriate for C++).
    Quote Originally Posted by Adak View Post
    io.h certainly IS included in some modern compilers. It is no longer part of the standard for C, but it is nevertheless, included in the very latest Pelles C versions.
    Quote Originally Posted by Salem View Post
    You mean it's included as a crutch to help ancient programmers limp along without them having to relearn too much.

    Outside of your DOS world, your header file is meaningless.

  10. #10
    Registered User whiteflags's Avatar
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    You do know that main returning nonzero means that the program exited under faulty or erroneous conditions?

    And I don't see a problem with usig a function parameter at all.

  11. #11
    C++まいる!Cをこわせ!
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    There is no law for returned values. 1 can mean success and 0 can mean failure. It's up to the developer to decide...
    I won't be taking any sides on what's best, though.
    Quote Originally Posted by Adak View Post
    io.h certainly IS included in some modern compilers. It is no longer part of the standard for C, but it is nevertheless, included in the very latest Pelles C versions.
    Quote Originally Posted by Salem View Post
    You mean it's included as a crutch to help ancient programmers limp along without them having to relearn too much.

    Outside of your DOS world, your header file is meaningless.

  12. #12
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    Quote Originally Posted by Elysia View Post
    There is no law for returned values. 1 can mean success and 0 can mean failure. It's up to the developer to decide...
    I won't be taking any sides on what's best, though.
    It is however a good idea to try to keep it the same throughout the system, and not "mix and match", because sooner or later you will find yourself having to look up what the actual result should be.

    Many systems use "negative for fail", zero or greater is OK. This of course falls down if you return unsigned integers (or pointers)...

    --
    Mats
    Compilers can produce warnings - make the compiler programmers happy: Use them!
    Please don't PM me for help - and no, I don't do help over instant messengers.

  13. #13
    C++まいる!Cをこわせ!
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    Yes, the best way would actually be to creates defines in some header file and use through your project.
    Returning 1 for failure in one and 0 for failure in one is not what I'd recommend, as you say mats.
    Quote Originally Posted by Adak View Post
    io.h certainly IS included in some modern compilers. It is no longer part of the standard for C, but it is nevertheless, included in the very latest Pelles C versions.
    Quote Originally Posted by Salem View Post
    You mean it's included as a crutch to help ancient programmers limp along without them having to relearn too much.

    Outside of your DOS world, your header file is meaningless.

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