That's not what that does, the answer to the code you wrote is 192 because you're multiplying the same size factor twice.
The first one has size 3, because there are 3 elements in the array. The second one has size 8 because an int64 is 8 bytes.
You don't have to like it
I should write instead: sizeof(int64_t[3]) / sizeof(int64_t) for length of array.
This does help my argument that Javascript length on a Unicode string should return bytes though :)
That's not what that does, the answer to the code you wrote is 192 because you're multiplying the same size factor twice.