Question

What does this code mean?

struct foo_t {
    int a;
    int b;
} foo[10] = {{0,0}}

foo[0] is {0,0}, but what about the rest?
How does the C standard handle this?

ADDED. I founded an exhaustive answer here. I think my question should be deleted.

Answer 1

The entire array will be initialized with structs with the value 0 for both a and b. This is similar to the following case with a primitive value:

int foo[10] = {0};

Where every integer in the array will be initialized with the value 0.

The C99 standard specifies the following:

If there are fewer initializers in a brace-enclosed list than there are elements or members
of an aggregate, or fewer characters in a string literal used to initialize an array of known
size than there are elements in the array, the remainder of the aggregate shall be
initialized implicitly the same as objects that have static storage duration.