Return Variable

This is a discussion on Return Variable within the C Programming forums, part of the General Programming Boards category; Hi There, I'm new with C, and trying to learn it on school. We have to do a little project ...

  1. #1
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    Return Variable

    Hi There,

    I'm new with C, and trying to learn it on school. We have to do a little project on our own and my question is:

    Is it possible to have more then 1 return variable in a function.

    I'd like to create a function that has 3 inputs and 2 outputs, but i cant find it in my book.

    I hope you can answer my question

    - SpoiLeD

  2. #2
    cwr
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    could you able to give a little bit more explanation ?

    i cant really figure out what they mean.

    - The global variable is not working for me, because the variable changes in the function.

    - SpoiLeD

  4. #4
    cwr
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    Using global variables:
    Code:
    int x, y, z;
    
    void f();
    
    int main(void)
    {
        f();
        printf("f() returned %d, %d, %d via globals\n",x,y,z);
        return 0;
    }
    
    void f()
    {
        x = 3;
        y = 4;
        z = 5;
    }
    Above, the function f() effectively returns values by changing global variables. This is the stupidest method possible.

    Using a struct:
    Code:
    struct foo { int x, y, z; };
    
    struct foo f();
    
    int main(void)
    {
        struct foo bar;
        bar = f();
        printf("f() returned %d, %d, %d via a struct\n",bar.x, bar.y, bar.z);
        return 0;
    }
    
    struct foo f()
    {
        struct foo t;
        t.x = 3; t.y = 4; t.z = 5;
        return t;
    }
    Above, f() returns a struct, containing 3 fields.

    Using pointers:
    Code:
    void f(int *, int *, int *);
    
    int main(void)
    {
        int a, b, c;
        f(&a, &b, &c);
        printf("f() returned 3 values using pointers: %d, %d, %d\n", a,b,c);
        return 0;
    }
    
    void f(int *x, int *y, int *z)
    {
        *x = 3; *y = 4; *z = 5;
    }
    Above, f() is passed the addressed of each variable in main, and sets them by dereferencing.

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    i do not understand what u want exactly from these statements:

    >>Is it possible to have more then 1 return variable in a function. (Explain more)

    >>I'd like to create a function that has 3 inputs and 2 outputs, but i cant find it in my book. (explain more)

    maybe the following code might help:

    Code:
    #include <stdio.h>
    
    
    int returnf(int a, int b, int c) { // function takes three inputs but returns one variable depending on which is zero
    
      if(a == 0 || b == 0) // to check if either the 1st or second argument is zero
        return a;
    
      else
        return b;
    
    }
    
    void main(void) {
       printf("function returns: %i bcoz either a or b is zero\n", returnf(2, 0, 5));
    
       printf("function returns: %i\n", returnf(0, 4, 1));
    
       printf("function returns: %i", returnf(5, 5, 1));
    
       getchar();
    }
    Any further questions? Glad 2 be of service...

  6. #6
    cwr
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    sidideas,

    The original question is quite clear, they want to return several values. A function only ever returns one type, but multiple values can be simulated using the methods I described above.

  7. #7
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    Thank you very much cwr for helping

    I do understand it now by those examples..

    And now the program works by using the pointers

    Thanks!

    - SpoiLeD

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