Arrays: accessing array elements by inverting the index variable with the array itself yields the same result

Question

So the code looks like this (you can access this fiddle here (Click me):

#include <stdio.h>

int main()
{
    int a[5] = { 6, 2, 7, 3, 5 };

    for (int i = 0; i < 5; i++){
        printf("%d ", i[a]);
    }

    printf("\n");

    for (int i = 0; i < 5; i++){
        printf("%d ", a[i]);
    }

    return 0;
}

And this is the output:

6 2 7 3 5
6 2 7 3 5

Apparently, he made a mistake when indexing the array, and inverted the index variable with the array itself. What he found out is that it still prints the same values. This might be a silly question, but again, I don't know much about these types of cases, and this itches me to find out why it's happening what's happening here.

Thanks

Answer 1

x[y] is equivalent to *(x + y) which is equivalent to *(y + x) which is equivalent to y[x].