Iterate through a C array

If the size of the array is known at compile time, you can use the structure size to determine the number of elements.

struct foo fooarr[10];

for(i = 0; i < sizeof(fooarr) / sizeof(struct foo); i++)
{
  do_something(fooarr[i].data);
}

If it is not known at compile time, you will need to store a size somewhere or create a special terminator value at the end of the array.