How can I loop through variables by their names?

November 19, 2022

Suppose I have N float variables x0, x1, x2, …, xn.

I basically want to loop through each of them and sum them all in a final variable sum.

I’m in a context where I cannot make use of data structures like arrays, vectors, etc. If it helps, in my context N is always less than 10.

Is it possible to make a for loop to do this?

My first thought was using macros like the concatenate (##) or something like that but I guess it won’t fit my case.

>Solution :

not sure whether it fits your needs, but you can try something like:

#define SUM_X0 (x0)
#define SUM_X1 (SUM_X0 + x1)
#define SUM_X2 (SUM_X1 + x2)
#define SUM_X3 (SUM_X2 + x3)
#define SUM_X4 (SUM_X3 + x4)
#define SUM_X5 (SUM_X4 + x5)
#define SUM_X6 (SUM_X5 + x6)
#define SUM_X7 (SUM_X6 + x7)
#define SUM_X8 (SUM_X7 + x8)
#define SUM_X9 (SUM_X8 + x9)

int main(int argc, char* argv[]) {

    int x0, x1, x2, x3, x4, x5;
    if (scanf("%d %d %d %d %d %d", &x0, &x1, &x2, &x3, &x4, &x5) != 6) {
        printf("error");
        return 1;
    }

    printf("%d\n", SUM_X0);
    printf("%d\n", SUM_X1);
    printf("%d\n", SUM_X2);
    printf("%d\n", SUM_X3);
    printf("%d\n", SUM_X4);
    printf("%d\n", SUM_X5);

    return 0;
}