CODEWITHSUNDEEP
cstruct
ieattacos9
ieattacos9

Reputation: 33

Is there a way to loop through multiple structs, like through an array?

Is there a way to loop through structs and assign a value to their members during the process?

I'm not really sure if I composed the question correctly, so I'll try showing it in code, that is of course invalid, but hopefully serves as better example: 

struct example {
    int x;
    /* ... */
};

struct example s1;
struct example s2;

int *structs[] = {
    s1.x,
    s2.x
};

int main(void) {
    for (int i = 0; i < 2; i++) {
        *structs[i] = i;
    }

    return 0;
}

Basically, I need to automate the process of assigning values to multiple structures, but I don't know how. Is this even possible in C?

Upvotes: 3

Views: 814

Answers (1)

Jonathan Leffler
Jonathan Leffler

Reputation: 754820

If you fix a bunch of trivial syntax errors, you can come up with:

struct example
{
    int x;
    /* ... */
};

struct example s1;
struct example s2;

int *structs[] = { &s1.x, &s2.x };

int main(void)
{
    for (int i = 0; i < 2; i++)
    {
        *structs[i] = i;
    }

    return 0;
}

Alternatively, you could use an array of pointers to structures:

struct example
{
    int x;
    /* ... */
};

struct example s1;
struct example s2;

struct example *examples[] = { &s1, &s2 };
enum { NUM_EXAMPLES = sizeof(examples) / sizeof(examples[0]) };

int main(void)
{
    for (int i = 0; i < NUM_EXAMPLES; i++)
    {
        examples[i]->x = i;
        // ...
    }

    return 0;
}

Both compile — both work.

Upvotes: 3

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