C structure initialization

Question

I got the following code from internet:

struct {
   int x;
   struct {
       int y, z;
   } nested;
} i = { .nested.y = 5, 6, .x = 1, 2 };

The result is:

i.nested.y = 2
i.nested.z = 6

But I don't know why,the article from the net doesn't give any explanation.

Answer 1

Non-designated initializers operate always on the next element in the structure. So the latest 2 operates on what comes after .x, which is .nested.y. In the same way the 6 goes for the nested.z.

If an initializer has several values for an element, the last in the list wins.

But if you have compiler that implements designated initializers, there should be no reason not to use them. The example that you are giving is very much far fetched and not of much educational value.